So, you want to play a fun healing support, or refuse to play the brain dead boring Sona or Sorraka. I have good news for you, if you like the butt clench saves of Zillian, the burst heals of Sorraka/Sona, and the targeted slows of doom, of well, Zillian. Kayle is the support for you, now you may ask, "why not just play Kayle mid/top?", well to be honest Kayle is kinda **** as a carry right now, so we play her as a support who doesn't need to do anything but peel and heal.

Pros:
[*] You heal for a lot
[*] You give a giant speed boost
[*] You Make people Immune to damage for 3 seconds on a fairly low CD
[*] You reduce armor and magic res by a lot
[*] 55% targeted slow
[*] Can bait dives with your ult

Cons:
[*] You need ardent to start having an impact
[*] When your ult and heal are on CD it feels like you do nothing
[*] Your heal is on a fairly long CD
[*] You do no damage with a full support build
[*] You shouldn't be playing Kayle support if you want to build damage
[*] You get flamed 50% of the time no matter how well you do
[*] You get blamed for everything, this isn't Kayle specific, every support and jungle main deals with this