(2023-02-04) The effect that allows you to play an additional land that turn is cumulative with other effects that do so, including itself
If youre a Commander player, this is easy: pick up Dance of the Elements or Blight Curse
With Rattleclaw Mystic, a green creature that taps to add either green, blue, or red to your mana pool, can only be played in decks that at least have all three Temur colors
That fact alone makes it quite flexible around blue removal spells
In terms of the downsides, this kind of promotion is akin to a lottery, and may need to be regulated as such
This is one of the few protection spells that can also wind up being a win condition, but youll want to make sure that you cast it at the right time