Agate Instigator turns creature entries into damage to every opponent, with offspring offering a way to establish two copies from one spell. Paying the additional offspring cost creates a 1/1 token copy when the original enters. Once both are present, every subsequent creature entering under your control can trigger both Instigators, making even ordinary token production much more threatening.
The offspring token is another creature entering, so the original Instigator sees it and triggers. The token does not trigger from its own entry. That gives you an initial point of table-wide damage before the pair begins rewarding later creatures. Offspring must be paid as part of casting the spell; it is not an ability you can buy later after the original is already in play.
Krenko, Mob Boss and other repeatable token makers provide a steady supply of triggers. Solphim, Mayhem Dominus increases the damage, while Purphoros, God of the Forge adds another payoff for the same creature entries. These pairings suit red token decks that want to win without relying entirely on attacks connecting.
Decide whether to pay offspring according to the turn's available mana. Casting only the two-mana creature may let you follow it with a token spell immediately, while paying four total establishes the stronger recurring engine. Neither version needs to attack to contribute, so protect the bodies and let the rest of the deck supply creatures that turn their small individual triggers into meaningful pressure.
