Plague (Casual)

At the beginning trigger Liliana's Caress and Raiders' Wake with Vicious Rumors, Burglar Rat, Ravenous Rats and Drainpipe Vermin (mostly for defense, but pay attention to have 1 open mana!) or Liliana Vess.
Choose the cards that can pull you back and make them discard (trigger!) with Duress and Toll of the Invasion (you'll have a token from this, good for defense too).

Painful Quandary is the key for winning. They can pay with life or discard, which also costs life, when they do literally anything :D

And if they don't have anything to discard, there's Shrieking Affliction and Davriel, Rogue Shadowmage.

Rat Colony is good for attacking and defending, when you have a lot of rats on board. Also more creatures attacking, more triggers to Raiders' Wake.

If you have the enchantments and a couple of creatures on the battlefield, Gray Merchant of Asphodel can be lethal, but it surely will lift your life total to be safe enough to win.
Also if you have more life Crypt Rats can be a good board clear.

And you can search for anything you need with Liliana Vess or make them discard any time with Davriel, Rogue Shadowmage.

Bojuka Bog slows the deck down a little, so use it only if they played from their graveyard.