* Use a one handed weapon to be able to air dodge better. I recommend the crossbow or marksman rifle as they have a good mix of high damage shots, fast bullets, and long range. They let you stay very far away from enemies. The high damage single shots lets you spend more time dodging.
* Leave the small crab spawns alive as long as possible to avoid too many dangerous enemies spawning at once. Only kill the the little crabs if there's nothing else left.
* Focus on killing enemies that use projectiles and then ones that move quickly.
* I used the ice ability to freeze dangerous enemies. It also has a large aoe so it can be shot around corners to damage them without exposing yourself.
* Always be moving. I was constantly making a circle around the outside of the arena, using the large pillars as cover.
It'll take at least a few tries.