Ishida's Antithesis deals with X-axis as long as he can tank Kira level wounds and continue which he should be more than capable of. Ichigo beats Ken with low to mid diff depending on if he goes all in from the beginning like he did with Yhwach (in which case Ken fucking dies). I'm Actually not sure how strong Ichigo was at the end of story because the fight was very short and linear but depending on how you scale him compared to soul king (literal god in Bleach) he might one shot Ken, I'm gonna have to reread tho.