Kayle <--- Great sustain. Build her AD, start with E, second is Q, then W... or if you wanna do W then Q that works too.
If you aren't sure on what her abilities are, her E gives her range and a small AOE, W is her heal+movement speed to target champ, and her Q is her slow+Damage (damage based off AD), and obvi her ult is invuln to target champ.
And i know what you are thinking. 'This guys an idiot, this is a support champion'. yes... she is support. but she is a fighter support. so she has a greater chance at being able to live longer in say a solo lane or maybe even invading enemy jungle. Her cooldown's aren't bad either. They are very reasonable. The only negative i see in her, is mana. Its drained so fast. But if you play smart (which you always should) you'll do great with her.
But this is just my opinion. maybe give her a try sometime.