Here is the full list of all 46 Trinity Fusion achievements.
Fuse two of your counterselves for the first time
Defeat 150 enemies
Purchase and equip a Psychic Augment
Die at least once
Reach the In-Between
Make it through The Wastes
Clear a curse
Equip your first Powerup
Leave The Outskirts
Complete the tutorial
Travel to every Location in the Multiverse
Defeat 3 enemies without touching the ground
Defeat the Lens Guardian
Defeat the Ewer Eminence
Defeat Typhon Two
Defeat Steward One
Purchase and equip the Resurrection Psychic Augment
Start a run with 5 Psychic Augments equipped
Complete a 3-skull arena in the In-Between
Complete a Hard platforming challenge in the In-Between
Equip 5 powerups in a single run
Complete a run on either Survival or Veteran mode
Complete a run on Hardcore mode
Reach Power level 15 during a run
Use the weapon upgrade bench for the first time
Defeat 20 Elites
Defeat 3 enemies with a single Glitch Dash
Get Claw 17 to safety
Defeat an enemy with an effect triggered by an Evade
Make it through the Ewer City
Make it through Fortress
Leave the Factory
Make it through the City Walls
Make it through the Underground Labs
Leave the Forge
Make it through Subterraria
Defeat 800 enemies
Defeat 2000 enemies
Evade 100 attacks
Evade 500 attacks
Dismantle 300 weapons
Defeat 10 enemies by dropping them into lava
Unlock 50% of the Enemy log entries
Defeat the Extant Decay
Defeat the Amalgamation
Defeat the Ewer Hypervisor