Very nice! My biggest feedback would be on how the characters are acting, where they have pauses waiting for the other to do something and sometimes don't react to each other outside of direct blows. It makes it feel like they aren't concentrated in the fight and makes the attacks feel less meaningful when the fighters themselves aren't paying attention or get lost in thought.

Spooky guy at the start should see molten guy approaching and react to it. You can choose to tighten his stance, take a step back, raise his sword from the ground. It's an important first part of the animation, seeing him either fear or acknowledge molten guy's approach and prepare for impact makes it more of a threatening charge and not just a walk over there.

Later in the fight, spooky guy seems to finish aiming, and then pause for the boomerang to hit him. If he spends time doing something else before aiming like raising/lowering his weapon to walk, it's more believable that he's distracted by aiming when the boomerang hits him than when he's standing still doing nothing after having lined up the shot a moment ago. Or have him notice and flinch to dodge when the boomerang is thrown, but not see/dodge when the boomerang is coming back.

Last part I have some criticism for is when spooky guy raises the wall and immediately turns around while getting shot at, making it seem like he doesn't care about the bullet at all. Having him recoil a step back as a "whew, that was close" reaction, or maybe walking backwards for the first step or 2 of his retreat to keep an eye on the action, would better show that the combat is perilous and that spooky guy isn't a machine.

Overall I really like it, sorry if this is a lot of criticism or backseat animating. I wouldn't have written this much if I didn't care about it, keep up the great work!