The following stages were the ones I used to get the S ranks.
Stage 01 - Temple Gate
Have at least two chi charges, build a combo of about 80 hits, and avoid taking more than 20% of your health in damage.
Kill the first three enemies and build your combo with the next waves. They have only one attack—a jump followed by a crouch punch. For the big monk, use the standard chi attack (X+A) when he turns red. If you run out of charges, wait for him to attack you. As soon as he finishes, jump and chain attack him (hold X). He’ll flinch and block, allowing you to jump-break his block. At this point, you should have another chi charge. After he’s dead, mop up the four adds that appear.
Stage 02 - Break
Build a combo of about 80 hits and take no damage.
This stage is heavily weighted on time. Chain attack the boss until you can jump-break him. Repeat. While you can use chi attacks on his uppercut, I found it unreliable. He is much less dangerous in the air, so focus on jump chain attacks rather than attacking him on the ground. Once he’s dead, mop up the four adds, ensuring you take no damage. Chi attacks against these enemies are recommended.
Stage 03 - Zen Room
Build a combo of about 80 hits and avoid taking more than 20% of your health in damage.
As soon as the fight starts, roll forward and parry both pole monks (with a single parry). Then alternate between them by rolling into melee range, parrying, and hitting them three times. Don’t be greedy, as they parry you while airborne. Avoid using chain attacks to break their guard; if they block, roll to the other monk and repeat the process. After they’re dead, build your combo with the adds. At some point, the boss will join the fight, but focus on the adds first. Once they’re dealt with, treat the boss the same as in Stage 02. When the four pole monks drop, prioritize them before finishing the boss.
Stage 04 - Swordsman
Unlock the low kick move, build a combo of about 50 hits, and avoid taking more than 40% of your health in damage.
At the start of the fight, roll towards him and parry his attack. Repeat until you pin him at the back of the arena. From there, execute two attacks followed by a low kick (parry + X). He will try to parry your third hit 90% of the time, so this combo breaks his parry consistently. At about 50% health, he’ll start using a red low attack and spam it until you reduce him by another 10%. Use this opportunity for chi attacks. Afterward, he'll mix parries with low kicks, making it unpredictable. Low kick into jump attack can reliably avoid his counterattacks, so stay airborne more often until he's defeated.
Stage 05 - The Critical Hit
Have at least two chi charges, build a combo of about 50 hits, and avoid taking more than 20% of your health in damage.
Jump into the middle of the arena for the chi flask, and use it to chi attack one of the big monks. Repeat for the other monk. The last monk will charge at you while adds spawn. Build your 50-hit combo by jump chain attacking as soon as he finishes his attack. Once your combo is complete, keep using the chi flask and chi attacks on the enemies. Always use the standard chi attack, as it’s the most reliable.
Stage 06 - Dragon Kick
Equip the Deflect Wave, build a combo of about 50 hits, and avoid taking more than 20% of your health in damage.
The first four adds are a parry test. You can anticipate their attacks by watching for the black fog around them before their "oi" sound. Once they’re dead, treat the boss the same as in Stage 02. At about 50% health, he’ll spawn three adds. Focus on the boss, as red adds will respawn if killed while he’s alive. His red attack is slow, so punish it with a chi attack. Mop up the remaining adds once he’s defeated.
Stage 08 - Circle of Lotus
Build a combo of about 30 hits and avoid taking more than 20% of your health in damage.
The boss’s ground red attack (indicated by a low attack exclamation mark) is slow and punishable with a chi attack. Keep this in mind throughout the fight, as it's 50% of the damage you will deal to him.
At the start, dodge the first attack and then poke him three times before retreating. If you miss the poke or see him rushing toward you, wait for his attack before approaching again. At 60% health, he spawns circles and blocks until pushed to the next phase. Chain attack him to break his guard and retreat. Always wait for the black circle to be positioned at his back before initiating a combo. At 40% health, he combines his previous patterns. Use poke-and-run tactics and break his guard when necessary.
Stage 09 - Tomb Entrance
Equip Light Boots, build a combo of about 80 hits, and avoid taking more than 20% of your health in damage.
Begin by waiting for the bomb enemies to jump back, then kick the first bomb toward them to take out all four. For the second bomb, kick it to eliminate two enemies, then mop up the rest. Deal with the six new bomb enemies, then hug the stone giant’s right side. If he kicks, jump and chain attack. If he crouches for a hand sweep, hit him with a chi attack to make him flinch. Repeat until he’s dead; remaining enemies will flee. Break the pots to the north and time a bomb kick to damage the dagger girl as she appears. Attack her, parry when she teleports behind you, and finish her off.
Stage 10 - Bomb Rage
Build a combo of about 50 hits and avoid taking more than 20% of your health in damage.
Hit the jars and activate the bombs. In the second wave, avoid charging at enemies after kicking their bombs, as it may hit you. For the suicide bombers, run behind the two statues at the back; they often get stuck and explode there. The final phase is straightforward—use chi attacks to counter self-detonation or play it safe by running.
Stage 11 - The Vault
Build a combo of about 50 hits and avoid taking more than 20% of your health in damage.
This stage involves a puzzle. A small statue in the arena’s center awakens the big statues if destroyed, so avoid letting it break.
Start by moving left to kill the awakening crossbow statue while parrying the right one’s shots. Destroy the other statue to the north before going right. Move to the bottom right to handle the pike statues. Quickly kill the chipped crossbow statue and use two chi attacks on the northern one. Next, eliminate the three pike statues without letting them destroy the center statue. Parry their attacks carefully. Three more pike statues will drop—finish them. Then, kill the dormant crossbow statues, chip away one big statue, and finish the other. Once one big statue is killed, the other awakens, so ensure it’s nearly dead beforehand.
Stage 12 - The Shadow
Build a combo of about 50 hits and avoid taking more than 40% of your health in damage.
Start by attacking her; she’ll teleport behind you. Parry and chain attack her to build your combo. Repeat this until she teleports again. When her health drops to about 60%, she’ll use her red grab attack. Counter it with a chi attack, then run towards her and repeat until she splits. At this point, she’ll begin using her low attack. While dodging is possible, the other clone may hit you mid-air about half the time. It might be easier to accept the lower hit and focus on attacking and parrying. Most of the damage comes from counter red attacks, so some RNG is involved.
Stage 13 - The Guards
Equip the Shadow Cut moveset, build a combo of about 80 hits, and avoid taking more than 40% of your health in damage.
Start by attacking one of the statues on the left. Then move to the center and hit the one there. When it wakes up, shift to the right and attack one of the right statues. By this point, you should have about two chi charges. Use one on the adds, leaving you with two small enemies to deal with.
The giant’s wave attack can be parried, though it will cause you to flinch. Use chain attacks to build chi, then use chi attacks if he goes red. If he starts a whirlwind attack, move away. Stay grounded unless he uses a stomp attack, in which case you should jump. If you’re airborne, he’s more likely to initiate the whirlwind attack. With the Shadow Cut moveset, chain attacks can quickly generate chi, allowing you to counter all his attacks and nullify his mechanics effectively.
Trivia: Parrying the wave with a chi attack will send it back to the giant. It’s not useful but a neat interaction.
Stage 14 - Underground Army
Equip Wonder Coat, build a combo of about 80 hits, and avoid taking more than 20% of your health in damage.
This fight revolves around maintaining combos. Move around the arena, avoiding bombs and using light attacks to keep your combo going. Once you hit 80 hits, focus on not taking damage. This stage heavily relies on RNG.
Stage 15 - Trials
Equip Light Boots, build a combo of about 50 hits, and avoid taking more than 40% of your health in damage.
This stage is time-sensitive. Run around destroying small statues. At some point, one of the large statues will awaken. Unless you destroy another large statue, the rest will remain dormant. Use this time to attack the smaller statues and handle any that wake up.
Once all the small statues are gone, focus on the dormant large statues. Chip away at their health without destroying them. Kill the third dormant statue to awaken the remaining large statues. First, take down the weakened ones, then the healthy one.
Note that once the large statues are defeated, the small enemies significantly reduce their use of red attacks, making them harder to counter with chi attacks. Therefore, deal with them before moving on to the large statues.
Stage 16 - Tomb Master
Play on easy, have three chi charges, and equip Wonder Coat and Shadow Cut. Build a combo of about 40 hits.
This fight focuses on critical hits. Roll towards the boss and use chain attacks until he goes red. Use a chi attack, then repeat. After the second red attack, he’ll start blocking, and the statues will activate. At this point, it’s a free-for-all between you, the boss, and the adds.
The adds can damage the boss, which he will use to heal himself. Focus on collecting chi flasks and hitting the boss during his red attacks.
Stage 17 - The Ambush
Play on easy, have three chi charges, and equip Reflector, Wonder Coat, and Shadow Cut.
This is a gimmick fight. Stay within the circle in the arena and attack continuously, moving around the edges of the circle. The Reflector will bounce most shurikens. When the orange enemies (who throw homing shurikens) appear, parry any shuriken that sneaks at your back.
When the first boss arrives, use your three chi charges to defeat her quickly. If you miss the window, wait for your chi to recharge naturally, as it refills from taking poison damage. The white enemies only deal minimal damage with kicks; use three attacks followed by a parry to avoid most hits. The last phase is similar—circle the symbol and use chi attacks on the boss.
Stage 18 - Sword Pair
Play on easy, have three chi charges, and equip Reflector, Wonder Coat, and Shadow Cut.
This is one of the easiest stages to achieve an S rank. Start by moving to the right and rolling under the girl. Avoid staying in the center of the arena between phases. Attack the mobs and use chi attacks on the bosses.
Since your chi recharges due to poison, use it frequently. Save one charge for the final phase in case a dagger enemy uses a red attack, as it’s hard to dodge unless you’re already airborne.
Stage 19 - Under Gate
Play on easy, have three chi charges, and equip Break Blaster, Light Boots, and Shadow Cut.
This is a straightforward fight. The first boss alternates between a normal jump kick and a red charge attack. Stay airborne as much as possible and use your recharging chi attacks to defeat her quickly.
The duo boss repeats the same mechanics but is less aggressive and uses the red charge attack infrequently.
Stage 20 - Fatal Chase
Play on easy, have three chi charges, and equip Wonder Coat, Light Boots, and Shadow Cut.
Another straightforward fight. Focus on using chi attacks whenever possible. Mobs drop plenty of chi flasks, and your chi constantly recharges due to poison. Black enemies use low kicks, and white enemies use jump kicks exclusively.
Stage 24 - Final Round
Build a combo of about 50 hits and avoid taking more than 60% of your health in damage.
Use the same strategy from Stage 04, but assume the enemies are in their final phase (expect low attacks). The orange enemy seems to have less health than the blue one, so prioritize him.
Although the stage can be frustrating at first, once you master the "roll into parry + low kick" strategy, it becomes manageable. After defeating the orange enemy, the blue one gains a new combo: three normal attacks followed by a slow overhead swing. The swing cannot be parried, so wait for it and counter after his third hit. He frequently spams this combo, so anticipate it whenever forced to parry.