True to its name, this abomination massively debuffs your entire team and to make things worse, it has insane regeneration. To fight it, you require overwhelming attack power, essentially you kill it in the first turn, or you lose. Alternatively you can prepare special counter items for this creature. The first one would be a story related craftable called manacatalyst. It will remove this creatures passives and will allow you to fight it like a regular giant. If you wish to brute force this fight, the final recommended item is radiant armor, it will help mitigate the severe debuffs this creature dishes out and allow you to focus on out damaging its regeneration. As of game v16, you cannot Mindbender it anymore. Using one on it will instead give it a 3-turn debuff making it take 50% more damage, making it much easier to burst down.