Mulligans
General Mulligans
What you keep depends on the matchup. Generally though, the spellstone is always a keeper. If you have deathstalker rexxar, he's also generally a keeper (good battlecry against aggro and good value against control).
An adaptation of this deck: https://www.hearthpwn.com/decks/1038913-fifth-best-deck-on-ladder-i-will-hunt-you-down
When playing that deck I noticed this deck has a very strong early/midgame. By throwing out the big cards the curve gets lower, making the deck even stronger in the early/midgame. I’d say this deck can get you to rank 5 if played well, but maybe it can get you even higher. I’m currently playing it at rank 4 and I think it’s a legit competitor of the ladder.
If you have the dust (or the card itself), the only chance I’d make is 1 Unleash the Hounds for 1 Deathstalker Rexxar.