IMO, Tats is so strong that you cannot get him in "conventional" ways. And just like some bosses RPG, in order to fight/restrain/challenge Tats, you will need a very specific "set up" and abilities.
Tats is already very OP, and in order to balance it out, he is heavily restricted. Thus, the "fun" part of this LN (in regard to character strength development) is how Tats struggles with those "abnormalities"
