Transcendent Physiology

I don't entirely agree with you but I can see why you'd think that would be a good candidate. personally I would say that a physiology beyond any one universe would be the most powerful. I would posit that 10th dimension physiology would be the most powerful physiology. Because then you would be quite literally everything. Like imagine if you took everything from every universe, reality, plane, and so on (known and unknown, reality and imaginary, an so on) and condensed it into a physiological being. that is a 10th dimensional being. if anyone can think of anything more powerful than that then I will be truly and sincerely impressed.

Technically a tenth dimesional being is transcedent, but i can see why you would make a distinction between them.

While I, in turn, can see why you (with all due respect) might be confusing transcendence for a tenth dimension being there is only crucial difference. A transcendent being (however powerful they may be) only transcends boundaries. A tenth dimension being (which I must reiterate my uncertainty about whether using the term being is even appropriate for such things) is simply EVERYTHING from EVERYWHERE in the multiverse/omniverse in one. to put it another way science has long sought a single Grand Unified Theory that will describe, explain, and elucidate the entire universe. If such a thing were one day discovered that would be transcendent knowledge (because it even example phenomena that at the time of its discovery were unknown). But if a Grand Unified Theory existed that could explain phenomena outside our universe then that would be a step towards tenth dimensional knowledge. Unfortunately such a formula (if such a thing even exists at all) would virtually without doubt be so complicated, paradoxical (because the laws of physics we are familiar with will no doubt differ from universe to universe), and esoteric that even the most illuminated mind would mind it maddening to explain that its discovery would be very nearly pointless. If I have failed to explain myself well than it is because I am drawing on examples of a grand scale to symbolize the concepts I am attempting to elucidate and not out of any desire to confuse, dishearten, or disenfranchise anybody.

4th wall physiology 

Perfection