A turtle's self doubt (Mikey×Shinigami story)

After a fail mission, Raph blames Mikey for causing Leo to get hurt and letting the bad guys to get away. This causes Mikey to think he's useless and doubts him self as a ninja. Meanwhile a mysterious witch girl is taking down the foot ' s operations putting innocent civilians in danger in the process but there's more to this girl than meets the eye. While that is happening Mikey finds out Shredder is planning something that will put his Brothers and Sensai in danger. Seeing this as an opportunity to prove himself Mikey will do anything to stop Shredder but at what cost ? Will Raph be able to talk him out of it ? And who's this mysterious girl ? (Rated T for later violence) (Mikey×Shinigami)