The Eroding Empire
Mysterious ball of red energy that can shape itself into a sword
Unfortunately Thybalt doesn’t really know much about this blade, except that it was given to his father by a (the?) Megatherion, with the request to hand it to Thybalt when he became of age.
Thybalt heroically used it to close the hellhole that plagued his home village for so long, but not before drawing the blood of some of his new friends.
The blade then reshaped into mundane metal. For now, Thybalt would very much like it to stay that way.