Some set should forbidden in arena.

So HellHades did a video just recently about Bolster set and Arena, and apparently it is quite broken.  From what I can tell, Bolster adds to the Shield set, and makes them both unremovable, so it essentially gives the team a massive boost in survivabiity for the first 3 rounds

He was taking on some plat teams which to be honest were pretty much decked out (i.e. +4 everything), and winning quite handedly.  

I suspect something would have to be patched to fix this

https://www.youtube.com/watch?v=X1pueld-t2s

It'll probably get reduced, but they will face a lot of fallout as I reckon a lot will buy the forge pass just to get this set, with the daily, weekly rewards and the final set you'll be able to make a set with strong HP - and thats pretty much all you need for it to be viable