I’m currently in the midst of trying to create my own combat animations for a combat system that I am making, but can’t seem to get my animation(s) to feel impactful. The animation just feels flat and static.
Any feedback/advice is deeply appreciated.
I suck at animations but i have learnt that you need to over emphasize movement and try use different easing styles to make things faster and such
Thanks! 
I appreciate the tip.
I’d say make it a bit faster at the end and maybe (if you want) do a follow up punch with the other arm.
Otherwise it’s really good!
You could try using different easing styles, the Back and Elastic easing style makes animations look more powerful in my opinion.
Mariel Cartwright explained a lot about making good animations at a GDC talk (you can find it on the internet). Overemphasising your keyframes, having a frame where the attack overextends then retracts hitbox, having a couple of frames of very emphasised windup, skipping frames and using smudges to hide it all work very well.
Here’s a tip from me: If you want your combat animation to look like it’s more powerful, try to make it so that it feels like character has to recover from using great force, because in animation from your video, character recovers from punching as if it was using as little force as possible, everything happened so fast and effortlessly, there was never a feel of great force being used.
Edit: After watching the video a couple more of times, i’ve concluded that same is true for throwing actual punch, it feels as if the character is lightly tapping something instead of punching it.
If the animation does not feel powerful enough, you can always add sound effects to boost your experience into any mood you want. Although I would consider these other answers if I were you.