I think the broadsword is a fairly powerful weapon in the right situations but the standtime after Mighty Blow can make it feel awkward to play. Swords are able to stick to targets because of heroic stacks however when you use your E to lunge at a target and they are moving away from you, the stand time will give them enough distance to get out of your range and consumes all your charges so you can't catch up again without using another ability.

I think a stand time reduction, or a small movement speed boost after a Mighty Blow could help it not feel so awkward, even if it sacrificed some damage for the ability to stick on a target better.