Board Thread:News and Announcements/@comment-6570478-20130331015820/@comment-5075764-20130402173052

The one and only reason that Leo, as a leader, would decide to accept Karai's offer of an alliance, is simply because he has no choice. The Kraang have proven enough times that they're more than formidable opponents, especially now that they have their powercell and portal working. With that, they're almost invincible, and if the turtles should fail then the whole world is at risk.

With all that in mind, they can't risk the world's safety over a vendetta, and the fact is, they will have a better chance of defeating the Kraang with Karai's help.

I'm not saying they should trust her (far from it), I'm just saying they have no choice. If they lose, Kraang wins, and the earth becomes one big poison gas bubble. With Karai, who is a skilled warrior, together with (I'm guessing) the rest of the Foot behind her, the turtles will have a better chance of fighting the Kraang.