({4} magic symbol) ({U} magic symbol) ({U} magic symbol) if each opponent has three or more poison counters, or ({6} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) otherwise available.
Steps
Cast
Echo of Eons by paying ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) , causing each player to discard their hands and draw seven cards.
Razorkin Needlehead triggers for each card your opponents draw.
Resolve the first trigger, causing the opponent to get a poison counter.
If the opponent has ten or more poison counters, they lose the game as a state-based action.
Repeat from step 3 for each remaining trigger.
If needed, cast
Echo of Eons from your graveyard for its flashback cost by paying ({2} magic symbol) ({U} magic symbol) , causing each player to discard their hands and draw seven cards.
Repeat from step 2.
Results
Each opponent loses the game.
Metadata
In 89 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).