Can I use Call to Glory between Cithria of Cloudfield's trigger and Pit Rookie's trigger when both are on the chain, spending the buff from one trigger before the other resolves?

Ruling: Yes, you can use Call to Glory between the two triggers. When Pit Rookie is played, both Cithria and Pit Rookie trigger simultaneously. As the active player, you order these triggers on the chain, then must pass priority to allow the first trigger to resolve. After Pit Rookie's trigger resolves (buffing Cithria), you regain priority as controller of the next item (Cithria's trigger), allowing you to cast Call to Glory using that buff before Cithria's trigger resolves.

Sequence:

• Play Pit Rookie, triggering both Cithria and Pit Rookie
• Order triggers on chain (e.g., Cithria trigger, then Pit Rookie trigger on top)
• Pass priority to opponent
• Opponent passes priority
• Pit Rookie trigger resolves, buffing Cithria
• You gain priority (as controller of next chain item)
• Cast Call to Glory, spending the buff
• Pass priority to opponent
• Opponent can react or pass
• Cithria trigger resolves

Nuances:

• You must pass priority and allow at least one trigger to resolve before casting Call to Glory; you cannot insert it between triggers without something resolving first
• Your opponent has a window to respond with removal after the first trigger resolves and before Call to Glory is cast, which would prevent the free cast
• Priority returns to the controller of the newest item on the chain after each resolution