InstantTempest
50/100
Plays about the same in 2HG as it does in any other format.
No 2HG-specific rules fire on this card — it plays much the same here as anywhere else.
Ratings start at a neutral 50 and are adjusted by rules derived from 2HG's structure — shared 60 life, shared turns, two opponents. They'll be recalibrated against real play rates once teams start submitting decklists.
X can't be 0. Target spell's controller exiles it with X delay counters on it. At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.
Fits the same colour identity — good candidates for your teammate's deck.
Suggestions are characteristic-based for now. Once teams submit pairings, this becomes a real co-occurrence score: played in X% of teams whose partner deck runs Ertai's Meddling.