I never thought about it as this complicated. I just thought that the TC spell needed ellone's power just to be used, like MP in other final fantasys, and that ulti will compress time with the compression point at herself, then absorbing it. you will say it cant be because time is infinite, but what if it can be, i mean, ulti would really be someone who would want infinite power,
time=infinite
time compression, it will keep happenening cause it's infinite
absorbing, she'll become like, ultimate, because she will keep absorbing the power of time.