Thats doable in 60-card formats by playing four copies but its very hard
Oh, and for good measure, each opponent also loses 3 life
Black Mage's RodBlack Mage's Rod, Dancer's ChakramsDancer's Chakrams, and Summoner's GrimoireSummoner's Grimoire were all contending for the same spot and it was hard to discard them
Ishai, Ojutai Dragonspeaker Ishai, Ojutai Dragonspeaker is a creature that gets big eventually, because if theres a thing that opponents certainly do in an EDH game, its cast spells
So much so that, after touching a quick low, many cards did an about-face and are spiking once again
They won't get more powerful if more than two permanents entered the battlefield under your control in a turn