Flow — Riftbound Keyword
Rule 829 — 11 rules
Definition
Flow is a passive ability keyword. It is functionally short for “You may play this from your trash for its flow cost. Then banish it.”
Related FAQ (1)
What happens when you play Abandon on a spell that was played for its Flow cost?
It will be banished when it attempts to leave the chain. Flow's "then banish it" means that if the spell would leave the chain after becoming a finalized chain item, and leaving wasn't instructed by its own execution, it is banished instead. Abandon returns the countered card toward hand, but that is still leaving the chain, so the Flow spell is banished. The same applies to effects like Kai'Sa, Evolutionary and Fizz, Trickster.