Rules FAQ
- You can trigger First Builder even if attached character is not participating in the challenge.
Title.
Unique character you control only.
Attached character gains a icon and the Builder trait.
Reaction: After you win a challenge in which you control a participating Builder character, search the top 10 cards of your deck for an attachment or location with printed cost X or lower, reveal it, and add it to your hand. X is the number of Builder characters you control. Shuffle your deck. (Limit once per phase.)
Link: Decklists
Rules FAQ