Board Thread:General Discussion/@comment-31981697-20170722123329/@comment-32182236-20180205110131

I found my buried answer-It's pretty early on in the discussion. I'll just copy/paste it again.

One SOUL's not enough for Flowey to gain his true form and hopefully be saved. Omega Flowey still wants to kill you over and over again.. Just like regular Flowey. And that's SIX souls. One SOUL won't restore his true form. However, since it's the determination SOUL, Flowey and that SOUL will share control of this Omega Flowey. Actually, the fact that Chara shared control of Asriel, but the six souls Flowey absorbed didn't (well, not until Frisk hepled) is further evidence the red SOUL has something to do with determination, or some kind of will.. But anyways, the two will share control, like Asriel and Chara. What happens next depends on what this determination SOUL wants to do inside Flowey.. They might team up, they might fight for control..

The asker may have meant Omega Flowey absorbing the determination SOUL too when he absorbed the six SOULS, which would DRASTICALLY change the answer, but they never specified-They just said "Flowey", so by default, we should assume they meant just regular Flowey.