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