Re: A new Red Kryptonite...
They could have Luthor send Kitty, as a nurse, to retrieve the chunks of the Kryptonite stilletto the medics pulled out of Superman in SR to attempt to lift Kal-El's blood in order to clone him - hence, Bizarro - but after being exposed to sunlight for the first time in three or four years, the elements of Superman's blood that process solar radiation, combined with the Kryptonite radiation, would cause a weird chemical reaction that would turn the Kryptonite blood-red. This would lead to Kal-El being rendered powerless - against his will, unlike in SII - while Bizarro goes on a rampage.
"My folks came to the U.S. as immigrants, aliens, and became citizens. I was born in Boston, a citizen, went to Hollywood and became an alien."