A card that creates Treasure tokens can also be helpful, since sacrificing your Treasure to gain mana will also trigger any Artifact death triggers like Judge Magiset Gabarnth's
Omnath costs more colors each time it appears, and in Phyrexian form, Omnath is WUBRG, with the black mana being Phyrexian for added flexibility
While I havent crunched the numbers myself, Im sure you can find which ones are most likely to appear
This includes cards like planeswalkers as they put loyalty counters on themselves, so Vorinclex can enable planeswalker ultimate abilities the same turn they enter the battlefield
This is a card good enough to see play in Pauper, Pioneer, and Legacy, so its safe to say itll play great in Draft or Sealed too
At the time of writing, I've played over 350 games of the format with a win percentage of approximately 64%