Chao Misadventures

Darnit, Karkat evolved into Neutral/Running. Ah well. I might as well make him a Sonic Chao. :3

Me: *buys a Shiny White egg with the intention of naming the newborn Rarity*
Shiny White Chao: *hatches with a crazy mad grin on its face*
Me: ... *names it Uboa instead*

Now the question remains... how shall I evolve this evil abomination?