Alakazam the Spellsharer

At the beginning of your upkeep, each player exiles the top card of their library with a Share Counter on it.

At the beginning of your end step, choose an opponent at random. They choose an exiled card with a Share Counter on it and put it into its owner's graveyard.

At the beginning of each player's upkeep, that player may choose up to three exiled nonland cards with Share counters on them and copy them. They may cast the copies and mana of any colour may be spent to cast them.