After a couple of days of fighting with Blender, I've managed to produce some decent animations for my swordsman character.
At first, the biggest struggle was the rig, but I found this handy dandy tool / package that allowed epics rig to work in Blender: https://forums.unrealengine.com/showthread.php?34619-ADDON-BLENDER-UE-Tools
Big thanks to the creator of this addon. Working with the mannequin rig is very easy and elegant. A perfect starting platform for budding animators.
My process for animating this character was first to record myself doing the motion in my living room, and then use that video as a background image for Blender. After matching the major poses, I began just eyeballing the animation and cleaning up. I finally got to use a little bit of my lessons in animating from college, so thanks Shawn Sedoff!
The animations (two attacks played back to back):
I first created the animations with the character matching my own footsteps naturally, then removed the root motion so he walked in place. Birdlay reminded me we're using a modern game engine and root motion is actually a supported thing, so I put it back in pretty quickly. Tomorrow, I intend to get these animations working in game and hitting things! (With my handy dandy damage component system none the less! I should do a blog on this system some day...)