Ryushikaze
Deus Admiral Parsimonius
I always figured that mako added a glow to the natural eye colour, so maybe her dark red eyes would instead just glow more xD
'Cause it would be weird to see Tifa with blue/green eyes O.O
I thought maybe it had to do with Jenova cells, but Zack didn't get injected with the Jenova cells, right? Or if he did, he rejected them or something, so it probably is the mako injections that all who enter into SOLDIER get, even if they end up being a low rank foot soldier like Cloud
Is mako a liquid or just pure energy that tangible to human hands? 'Cause Tifa probably, I dunno, took some from her mouth or nose when she inhaled...maybe...I dunno
It's the Mako infusion. Presumably, Tifa would have glowed a bit after Mideel, but it's not casually noticable in normal viewing, since our best examples of mako showerees are not openly glowing all the time.
And mako is a liquid. At least after extrusion. It can crystalize into a solid and move like one at times as well, much like magma.