Hearthpwn

Easy way to defeat The Steel Sentinel.
Mulligan for low-cost poisonous minions and removal spells, save Violet Illusionist until the end, so you can survive fatigue. Try to combo Pint-Size Potion with Shadow Word: Horror for efficient boardclear.

The only necessary card for this strategy is the Illusionist, everything else you can swap with other hard removal cards or minions with poisonous. Just remember to not put Psychic Scream (it does well with clearing the board, but your win condition is to mill the Sentinel) or any damage dealing boardclears, because they will not work.