Hive Mind triggers, causing each opponent to create a copy of Windfall.
Resolve the first opponent's copy of Windfall, causing each player to discard their hand and draw cards equal to the greatest number of cards discarded this way.
Each player who did not control Windfall's Pure Intentions triggers.
Resolve all Pure Intentions, causing you and the opponents to return to their hand all cards discarded by Windfall.
Repeat from step 6 for each remaining Windfall until you either draw from an empty library, causing you to win the game due to Laboratory Maniac, or until your opponents lose the game due to drawing from an empty library.
Results
Near-infinite card draw for all players.
Near-infinite draw triggers for all players.
Near-infinite self-discard triggers for all players.