He's a harder to cast three red mana on a four-drop 2/4, with one simple ability...when your red stuff would deal damage to a foe or their stuff
Spells cast from zones other than your hand and spells that were countered or otherwise failed to resolve are still counted by the coststorm ability
If my opponent says the chosen word twice, does Keeper of the Sacred Word get +6/+6
Note that specialize creatures can be of any color pair, so the Brawl rules say that if you want a specialize creature to be your commander, you must choose two colors
While red would kill for each and every two-power one-drop it can get its hands on, they are basically a dime-a-dozen in white
Rumbleweed is a little more specific to a land-in-the-grave deck, like Yuma, Proud Protector or Titania, Protector of Argoth