I think the idea of revenge already precursors a lack of moral shading here. It's not bullying if one returns malicious actions despite pure intent with likewise malicious action. The only reason one would feel it is bullying is when they've run the course of short term gratification of revenge...
Wow, a lot of shots from the fight scene are copied from Air Gear. Heck one of the fighters holds two sticks which looks like a cross which one of the earlier teams used to fight with. Not complaining tho, this comic is pretty satisfying in spite of it all.
This is like a poor man's "Chuunibyou demo Koi ga Shitai" but without the over the top imagination. This might either get a good low going or just be isekai gags till it runs out of fuel. Let's watch and see.