Liberator Eto

Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand or GY) by paying half your LP while your opponent has a Monster Card on their field or in their GY with an effect that can activate in the hand and/or Monster Zone, but activates in response to the activation of a card or effect to do so. You can only Special Summon "Liberator Eto" once per turn this way. This card's Special Summon cannot be negated. This card in the Monster Zone cannot be used as material for a Fusion, Synchro, Xyz, or Link Summon, also it is unaffected by monster effects activated on your opponent's field during your turn only.