I also didn't like Chihaya winning with her left hand. Not much believable. And I also don't like the idea of a Chihaya / Shinobu match with that handicap. I'd prefer a fair match. It would be more intense. Without unnecessary step-up moments. And a clear result.
Anyways I can see Chihaya reaching the new frontier of Karuta, the first both-hands player. Even metaphorically speaking, the right hand to reach Arata and the left hand to
wait for be reached by Taichi.
Taichi hasn't been mentioned in Empress's list, hasn't he? Probably to leave us with the doubt. Since basically refusing Arata he badmouthed Karuta, so cards could turn against him as punishment. Plus he used all his lucky credits to win the team tournament.