I just got bit by a bunch of bunnies for Shinobi_Soldiers. This was the only Shinraverse one, though, so I wrote it first. It's a sequel to this.
Warnings: Spoilers for some of the more recent Naruto chapters. (BTW, artimusdin, it seems Canon worked out the 'mako+Sharingan=?' equation for me. Though, I do have to rethink a lot of my plot ideas...)
"Shiva," Cloud whispered. "What the hell did the mako do your Sharingan?"
The were both squeezed into the small bathroom that was attached to their bunkroom, fresh from recuperating from the mako injections to become Third Class Soldiers. Zack had been in the middle of getting ready to take a shower when his reflection in the mirror caught his eye- his Sharingan had mutated, changing from it's usual three tomoe form into a ring around the pupil, six white 'tomoe' fixed into the black ring. His surprised shout had brought Cloud into the bathroom, and now both were transfixed by the sight.
"I'd heard rumors..." Zack admitted, "but I never thought they were actually true."
"Yeah. It was said that the Sharingan could evolve- but after Konoha was founded, the cost to make them mature was considered too great compared to the gain. It was also a practice of a more barbaric time, so it fell out of favor." Zack said. "To gain the first step, you had to kill your best friend- but that level of Sharingan, while powerful, caused the user to go blind from the strain. To get past that, and to the next- perfect- level, you had to take the eyes of your brother and back then, that meant death to the donor because they didn't have as great of medicine." The brunet gave the blond a wan smile. "Obviously, I never felt such a practice would be beneficial or ethical- but, apparently, I didn't have to worry. The mako did it all for me!"
For all that Zack sounded thrilled by the prospect, Cloud could detect a bitter tremor under his words and the older boy's smile was brittle at the edges, ready to shatter and split skin.
"Is it going to cause problems?" Cloud asked quietly. They'd already been having problems hiding Zack's 'normal' Sharingan, and Cloud could only guess at what might arise from this fortuitous, yet disastrous, turn of events.
Zack was resigned. "I don't know, Spike. I don't know."