Well, if Staff of Domination got the boot for being a "combo instigator" insofar as that Staff is not necessarily broken all by its lonesome, but unbanned presents an incentive, and relatively easy method of achieving, for infinite combos, then technically doesn't
Opalescence also fit that mold, except for being a thousand times worse?
With Opalescence and
Parallax Wave, I can get infinite card draw, infinite life, infinite tapped creatures (with
Kor Hookmaster), infinite untapped creatures (with
Volition Reins), while also creating permanent Armageddon (wherein all lands put into the battlefield go to the graveyard as a state-based effect when
Enchanted Evening is in play, meaning newly played lands cannot even be tapped for mana once), while also countering all spells anybody ever tries to play, while also exiling all permanents, while also being able to protect my entire field from mass enchantment removal, as CrazyPierre mentioned, by exiling all of my own permanents with
Glimmerpoint Stag.
With Opalescence/Parallax Wave, I am only susceptible to 1 card. Stifle. If you don't have Stifle, I get to do whatever I want to do for as long as I feel like it. My win condition is for you to deck yourself... I don't mill you, I just make the game hit turn 100+, and you deck yourself.
Turn 1: Adarkar Wastes, Sol Ring.
Turn 2: Mystic Gate, Parallax Wave.
Turn 3: [no land], Opalescence.
Turn 4: [no land], [at the end of the turn of the player before me and/or in response to threat to my field] Venser, Shaper Savant.
Turn 5+: Blink Venser with Parallax Wave to bounce all permanents in play, and bounce all spells played for the rest of the game.
Turn 12: death (for 1 player) by Venser/Parallax Wave beat down.