Riley Standard Legal Alchemy Legal Pioneer Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
Add on top of that evasion, ward, and getting a +1/+1 each time Valgavoth triggers that card draw, and you've got the perfect commander to build a red/black deck around.
I find that it's really valuable in: Any Color Combo with Green Ramp with the mana to easily abuse this
Opponents with decks whose curves extend to seven and play cards at random don't fear the Keg, they just respect it
Interaction A few counterspells help keep people honest when you have blue mana up to potentially stop their game-winning combo, or a pesky battlefield sweeper that will otherwise send your glorious Dragons to the graveyard
However, you could feasibly upgrade this deck into something thats much stronger as there are some really strong pieces here