Here is the full list of all 25 Zenteni achievements.
Build everything in the castle.
Find a tier 10 water hero.
Find a tier 10 non-elemental hero.
Find a tier 10 wind hero.
Find a tier 10 nature hero.
Find a tier 10 earth hero.
Find a tier 10 fire hero.
Defeat a tier 10 hero.
Complete the stained glass.
Discover all puzzles.
Discover all equipment pieces.
Discover all heroes.
Open a black box.
Fully equip a hero.
Complete all main quests in normal mode.
Read whole story.
Craft a tier 1 item.
Craft a tier 2 item.
Craft a tier 3 item.
Craft a tier 4 item.
Craft a tier 5 item.
Craft a tier 6 item.
Craft a tier 7 item.
Craft a tier 8 item.
Fully improve a hero.