When he ends up fighting Mr. Mxyzptlk, he definitely has all of [those feelings for Kara] fueling his blows.
In season 1, Supergirl had both the Kryptonian Kara Danvers (Melissa Benoist) and Green Martian J’onn J’onzz (David Harewood), but season 2 saw the additions of Daxamite Mon-El (Chris Wood) and White Martian M’gann M’orzz (Sharon Leal).
While the first season of Supergirl dealt with a whole prison of aliens unleashed on Earth, season 2 has introduced a myriad of even new aliens.