Disclaimer: Don't own it. Blegh.
A/N: Don't ask...
o-o-o
Castiel would never understand sibling rivalry. The idea of causing harm to your own brother or sister... granted, he had seen it occur between the Winchesters on many occasions. Initially, he had arrived in a motel room while the two wrestled to the floor, fighting for the remote control. Then there were the times they hit each other, stole from each other, and the casual insults they threw. Strange.
And yet, as he and Uriel circled each other in that warehouse, Lucifer's sword glinting in the dim light, he suspected he finally understood.
And that was truly cause for alarm.