You're on the right track but not quite there. Picking who you join is more like finding your prey rather than defending from an invasion as you'd normally see. It should be more like you custom how you want it to go like in practice. Levels should be chosen however the schools being chosen will be a prey-like effect. If they are able to choose schools then someone who does very well against those schools can easily win while being able to customize their deck accordingly to easily defeat them with the proper shields, dispels, and attacks to take them down. Pvp would be even more insane.
when i win in a ranked pvp i get few arena points but when another person wins they get a lot of arena points and what they win gets subtracted from my points why is that????