All in sort of team. It is possible to kill Ultra Heroine Z in one go without a max CE Okita friend as well, unfortunately there wasn't one on friend list at the time to use as an example. Fairly consistent team, though MHX is a glass cannon. If she is under 7k HP and dragon wont die, sub in a Mashu, (also put Mashu in slot 4 so you can try to taunt UHZ and get her killed so MHX comes back in fast, unlike me in this video). It's also possible to kill UHZ if MHX dies before using NP, but a bit of luck is probably required at that point.
Should also be able to replace Kaleidoscope on Artoria with Imaginary Number Magic as well. I was using an event CE on her before, but found I was able to fill up all 3 member's NP bars before UHX more consistently if I used some sort of NP starting CE.