Tengu format ruling
Dimensional Prison

Card effect (current official text)When an opponent's monster declares an attack: Target that attacking monster; banish that target.
Rulings
- If that target's battle position is changed (or if the attack is negated), it is no longer an attacking monster, and is not banished when this resolves.
- If that target becomes affected by "Fiendish Chain", it is still an attacking monster until the chain resolves, and IS still banished.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.