First of all, I really like the multiplayer mechanic of a PVP arena. And the fact, that empty spots will be filled with bots.
However, there is the big issue I have. Filling empty spots with bots so every person trying to play the Arena is nice, but after playing a few Arena matches I see one problem:
The bots are way too OP.
I'm not suggesting to turn the bots into opponents you can snip away with no power, but please make them a little weaker. No matter how, I always ended up with bots in the match that are so strong that they one-shot my team, even with it being fully leveled up, and even after using a guide. This takes a lot of fun out of the game and gets far too fast very frustrating.