You wish. Did you know then can shuffle a bunch of their ‘Symphony’ cards after you play Helya with some plagues… after they play the Wheel? Oh, and if you haven’t destroyed their weapon, they get healed instead.
That’s why I keep saying that things like the current aggro DH are some of the best things that could have happened to the meta in general.
If some reasonable aggro/tempo is gone, welcome to the world of Rainbow Mage vs Boom-Boom Warrior vs Wheel Warlock — what a ‘healthy’ bunch of ‘rock-paper-scissors’ 
, with the likes of Zarimi Priest somewhere on top.
‘Lol’ on you. Pure Plague DK isn’t playable now, however, most top ‘Rainbow’ DK lists, which do include removals for that case, run Helya and some plagues.
Not that it’s a great match-up for DK anyway — those plagues are not a panacea.