KingsBane Mill Rogue

Aggro Mulligans

backstab allows you to combo and kill early minions. There is only one leeching poison in this deck but it is a great draw against aggro if you have kingsbane as if you have a lifesteal weapon it will keep you alive. Tar creeper, doomsayer and mistress of mixtures will keep you alive. Shinyfinder often burns an early aggro minion and snags you kingslayer. 

Your win condition against aggro is living long enough with the tools you have to vanish their board and play one or two arcane giants. Aggro often has no way to deal with a threat of this size and will lose. Also buffing kingsbane with deadly poison x 2 and leechlife will give you a near unstopabable 5/3 lifesteal weapon. 

Control Mulligans

your vanilla win condition against control is to play valeera the hollow and use your hero power to play up to 3 giants in one turn. however with cards like twisting nether, psychic scream and large taunts in general it can be hard to send the giants face. Often you want to have kingsbane and buff it 4x with deadly poison (twice with the card, twice with the hero power) and 1x leeching life. This gives you 9/3 lifesteal weapon that helps prevent fatigue by shuffling into your deck and lifestealing for 9 every turn.