Spellbook Vendor

You don't choose a target for Spellbook Vendor's ability at the time it triggers. Rather, a second "reflexive" ability triggers when you pay {1} this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.

If a permanent has more than one Role attached to it controlled by the same player, each of those Roles except the one with the most recent timestamp is put into its owner's graveyard. This is a state-based action.

If two or more Roles controlled by the same player become attached to a permanent at the same time (perhaps due to an effect such as that of Doubling Season), that player chooses which one to keep and which are put into their owners' graveyards.

In rare cases, a spell or ability might attempt to create a Role token enchanting a permanent that it can't legally enchant (because of an ability like protection from enchantments). In such cases, the Role token isn't created.

Roles are colorless enchantment tokens. Each one has the Aura and Role subtypes and the enchant creature ability.