Honestly, something felt... off about him the whole time. I also kept in mind that this was a guy who suggested his [step]sister be married off to an abusive older man... for money.

Looking back, it's pretty clear that Asahi was (trying to) play us - he just kept telling us everything we wanted to hear. I was suspicious of his intentions the whole time - especially his focus on Yotsuyu - and the Red Kojin attack felt... uncannily well-timed, and without purpose. Needless to say, I wasn't overly surprised when the mask dropped... though the source of his hatred being Zenos was unexpected. Now that Asahi got the prisoner exchange negotiated, he didn't need to keep up the charade anymore.

The only thing I can't figure out is why he wants Yotsuyu's memories to return. Unless she has some special information he isn't privy to, or believes she'll share that information with the Domans, there's... no real point to it, and there's unlikely to be any love lost between them. Hmm...

Well, we know it's a trap. The only thing there is to do is spring the trap.