How does Draven work when deciding when to recycle a red rune for +2?

Draven, Vanquisher: Ability Timing and Cost

To clarify how Draven, Vanquisher's ability works regarding the timing of recycling a red rune for his +2 Might bonus, here is the official ruling based on the game rules and FAQs:

The Ruling

Draven, Vanquisher's ability ("When I attack or defend, you may pay [C]. If you do, give me +2 [M] this turn.") is a triggered ability that goes on the chain. The cost is paid on resolution, not when the ability is added to the chain.

Because the cost is paid on resolution, you do not need to commit to recycling a rune until the ability actually resolves. This allows you to wait and see if your opponent plays any defensive reactions (such as moving a unit or using a buff) before you decide whether to spend your Fury Power.

Sequence of Events

1. Trigger: Draven is declared as an attacker or defender. His "When I attack or defend" ability triggers and is added to the chain.
2. Reaction Window: Players have the opportunity to play reactions. During this time, you can use the Basic Rune Ability of a red (Fury) rune to recycle it and add [C] to your pool (Rule 160.2.b).
3. Resolution: When Draven's ability resolves, you are presented with the choice to pay [C].
   • If you have [C] in your pool (from a previously recycled rune or an Add ability), you may choose to pay it.
   • If you pay, Draven gains +2 [M] (Might) for the turn.
   • If you do not pay, the ability resolves without effect.

Important Nuances

• Cost vs. Effect: The "may pay [C]" is part of the ability's instructions, not an additional cost to play the ability itself. This is why it is decided on resolution (FAQ #8425).
• Frequency: According to FAQ #4341 and FAQ #3095, this ability triggers only once per combat (the first time he gains the attacker or defender designation). You cannot stack the +2 Might bonus multiple times in a single combat by recycling multiple runes. To stack the bonus, you would need Draven to participate in multiple separate combats in the same turn.
• Recycling: You can recycle a red rune at any time you have priority to add [C] to your pool (Rule 160.2.b). Since recycling is a reaction, you can do this while the chain is open or closed, provided you have priority.

This interpretation is based on FAQ #8425, FAQ #4341, and Rule 160.2.b. No official rule exists that contradicts this timing for "cost within instructions" abilities.