60 card mtg decks Green Massive Creature Deck - Powerful - Modern Legal - Custom Built - Magic The Gathering - Spider Man Magic the Gathering

The combo happens when you sacrifice it to Altar of Dementia, which lets you mill cards equal to its power

Infinity Elemental has the largest power on the battlefield (although it will tie other Infinity Elementals)

Cards that draw cards through damage, like Curiosity, will be great with Vivi, as will cards that trigger its ability another time, like Harmonic Prodigy

Alongside all your favorite land synergies, Bill will turn your creatures into real threats

Regarding EX cards, there's nothing written on them about limiting them to one per deck so this rule from rulebook applies [1] : When you are building a deck, you can have only 4 copies of a card with the same name in it, except for basic Energy cards