Castle Courtyard
Trial: Finish the Level after killing 3 Skeletons while mounted on a Warg
You will reach a section in a hall way with a bunch of sealed doors. After dealing some damage to the Skeletons, the Vampires will release a Warg. Do not kill ANY Skeletons unless you are on the Warg. There are only 3 of them. The 3rd will spawn after you kill the other two.
Maze Garden
Trial: Finish the level after killing 15 Mandragoras in less than 15 seconds.
This one is a bit luck related. I find they mostly spawn in groups to the left section of the start. Once you start seein a large group of them spawn, throw Holy water to kill the large group and then start to pick off the rest. If another group appears do not be afraid to use more holy water.
Castle Hall
Trial: Finish the level winning the Vampire War game losing no more than 3 pieces.
This one is 100% dependent on you ability to play a chess like game. You have 6 pieces so you cant lose more than half your pieces. Luckily if you do you can load the last checkpoint and try again. Best you can do is get to know your pieces. The Necromancer is your key to victory. They can Summon Zombies which pretty much only serve as a distraction and waste a turn of your opponents killing, they can attack anything within 2 tiles of them which is extremely important to know when placing them. They also avoid armour when it comes to damage, letting them take out Vampires in just two attacks. I just played defensively all game. I let Laura sent her pieces to me. The hard part is taking down her Necromancers. I ended up losing 1 piece of each for a total of 3 before winning.
Refectory
Trial: Finish the level and defeat the the Evil Butcher after he uses 15 objects in the Kitchen
This is a simple trial. Simply dodge his attacks, you can attack too if you want, just maybe stop if you hit 25% as we dont want to trigger his final form(Which is putting a pot on his head). He will eventually wander off and use something from the kitchen. Typical items are Meat which he uses to heal, Knives\Cleavers that he throws and a pot of what I assume is alcohol as he is able to breathe fire after drinking it. Once he uses 15 items, kill him and finish the rest of the level