Entrave-sort (Spellbinder)
Entrave-sort 
À chaque fois que la créature équipée inflige des blessures de combat à un joueur, vous pouvez copier la carte d'éphémère dont cette carte a l'empreinte et jouer la copie sans payer son coût de mana.
Équipement
Texte de règles (Oracle, anglais)
Whenever equipped creature deals combat damage to a player, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip
Légalité
Précisions de règles (en anglais)
2005-03-01
The creation of the copy and then the casting of the copy are both optional.
2004-12-01
Spellbinder's second ability allows you to create a copy of the imprinted instant card in the Exile zone (that's where the imprinted instant card is) and then cast it without paying its mana cost.
2004-12-01
You don't pay the spell's mana cost. If the spell has X in its mana cost, X is 0. You do pay any additional costs for that spell. You can't use any alternative costs.
2004-12-01
If the copied card is a split card, you choose which one side of it to cast, but you can't cast both sides. You can choose the other side later in the game, though.
2004-12-01
Spellbinder imprints a card only once, when it enters. Attaching Spellbinder to a creature doesn't trigger its "enters" ability.