Shinjiteita Nakamatachi ni Dungeon Okuchi de Korosarekaketa ga Gift "Mugen Gacha" de Level 9999 no Nakamatachi wo Te ni Irete Moto Party Member to Sekai ni Fukushuu & "Zamaa!" Shimasu!

This anime follows the story of Light, a young man betrayed and left for dead by his most trusted party members in the depths of a deadly dungeon. His only hope is a seemingly useless skill: the Unlimited Gacha. However, in his moment of greatest need, this power summons Mei, an extraordinarily powerful warrior whose loyalty is absolute.

Forged by betrayal and armed with his newfound ability, Light dedicates himself to a singular goal: revenge. The anime chronicles his journey from a desperate survivor to a formidable figure, building his strength and assembling a peerless group of companions to one day confront those who wronged him. It's a tale of vengeance, power fantasy, and the bonds formed in the darkest of places.