Say I'm playing Morrigan-3 and my opponent uses Ichi no Tachi's E and resolves it. He commits something and after it resolves I declare Morrigan's react. I commit 1 foundation for its cost, and resolve it by playing Ichi no Tachi's E "as though it were printed on this character." Can my opponent use Tag Along to negate Morrigan no Tachi and prevent me from copying any more Ichis he plays that turn? If he plays another Ichi and plays its E, can I use Morrigan's R on it too, or does it just fizzle [since I can't play the ability and can't > can]?
Tangentally related question - in a Twelve-1 mirror match, can Twelve use his R: to copy his opponent's Twelve R: and consume its "Once per turn" use? If so, can I copy his Twelve ability to copy my own Form ability? Does it matter if my opponent's Twelve is ready or committed?