Arms race is very similar to a rogue like game as if you die you start over and you start with nothing. I like to see this further worked on as there a few problems with it that just don’t make it rewarding to replay.
Currently right now it plays like a less efficient farm for legendaries and when you collect the new legendaries there will be no reason to play it.
It should be expanded on as you beat one arena you gain access to the next harder arena. I’d rather see this concept then just the one giant arena we have now. Say you start off with just your action skill and no skill points, when you beat the first boss you are given a certain small amount of skill points and move to the next arena/map. This would give the game mode a less of a linear approach that it currently has and something to work towards beating the next arena with a snowballing power curve that rogue-like games have.
Give each arena different drops that have a higher chance of being legendaries with each arena you complete.