Basically leading with your Lightning Fury to start off. Close the gap blind and use your Fend. Each hit counts towards the quest and you get her passive from the lunge on fend.

For heroes like butcher, bait them and use your blind before they close on you. So like with butcher, time your blind right before the stun from his charge. this way he cannot get the majority of the melee damage off while you are silenced. If you can get the lighting ball off at the same time you can turn the fight in your favor. Valkyrie does have a place here for ganking, or securing a kill in team fights.