Here is the full list of all 36 Trillion: God of Destruction achievements.
Defeated Trillion in its Final Form!
Defeated Trillion in its Dragon Form!
Broke through Trillion's outer armor!
Defeated Trillion in its Titan Form!
Completed all entries in the Gift Guide!
Amassed a variety of Active Skills!
Amassed a variety of Passive Skills!
Gave someone the best present ever!
Strengthened a weapon by +10!
Defeated Mokujin with one hit!
Inflicted 10 billion damage with one hit!
Unlocked "Holy Illusion"!
Executed Fever Time for the first time!
Retreated for the first time!
Reached the MAX level in a relationship!
Leveled up a skill to the max!
Got 100,000G!
Used Order for the first time!
Gave a present for the first time!
Challenged the Valley of Swords for the first time!
Used Interact for the first time!
Powered up a weapon or opened up a slot!
Performed a stat increase for the first time!
Trained for the first time!
Obtained every trophy!
Watched all the lovey-dovey endings!
Defeated Trillion with one of the first three Overlords!
Cleared Challenge Mode!
Watched the true ending!
Began a second playthrough!
Watched everyone's hot springs event scenes!
Affection Points have surpassed 1 billion!
Used every Death Skill!
Opened up all the Demon Seal slots!
Strengthened a weapon by +30!
Executed Double-Up for the first time!