I have been trolled so hard by those damned things. Even after they are hit and going down they can still deal 20 damage. Any advice on strategy against them?

For my Easy runs in particular I tend to run at them all guns blazing and not worry about my health. But during my Expert runs i tend to stop short before I reach them to either time my Jump Kick at them or Flame Chaser them down. They are 100% dumb.

I usually just try to time my dives at them, if you time it properly, they die and you take no damage and keep going. If you grind it a bit, you can get the timing down. If you notice that your timing is slightly off, you can dive attack them for the kill and have time to jump to the left and then continue without the explosion damage.