with flayer now being 7 tile range instead of 8 they are definitely way more endurable you can actually Whirlwind them from a distance properly now.
But the defense drain should stop at 0, instead of going negative
At 0 defense They pose still a great challenge but when your using a Recall potion to depth 200+ and your rooms are filled it leaves you way to vulnerable when within 20-30seconds your already -200 defense, with each new room you try to escape to having More monsters if not a situation ive met where i had More flayers on each side i tried to run to. and still has a far to big risk of death, even while using Unarmored at 100 it is difficult to survive
Capping Defense drain to 0 would balance out this monster perfectly
Just an IMO on the Monster