expert mode mech bosses are crazy

currently trying to beat just one of them in expert mode but I've only managed to kill them in normal mode.

I'm using the hallowed melee armor for the defense, along with angel wings, the triple balloon, Magiluminescence, and both healing Regen bands. i feel like i have enough movement to get around. but the stray hits keep adding up and I'm not killing them in time before i die.

just at a loss for what to do