Nerfs in season 4 were hard, there is no turning back, we are comming back for season 5!

Take what you prefer, but have 21+ in offense

Roles calculation:
Top: This lane is longer than mid and there are 3 bushes, I dont recommend playing against champions with bush mechanix it would be hard, top is high risk/reward lane for Kayle. The risky part is enemy jungler since we dont have any true escape mechanism, the rewarding part is when enemy jungler is atm on bot and enemy top laner is melee without hard gap close (gab closer champs are hell for kayle). Going top worths 2/10 or 12/10
Mid: This lane is shortest of all, it is not easy to gank unless you play lee sin, j4, rammus and other heavy gankers. If enemy team doesnt have strong ganker this lane may become rewarding, if you prefer agressive poking max Q. Mid worths 8/10 with AP build, AD build is very risky - 1/10 or 11/10
Jungle: Riot is planing more difficult jungle in next season, i wouldnt play jungle Kayle anymore. Worths 7/10 atm, 3/10 in season 5
AD carry: If you are planing to go ADC Kayle your team will blame you, but with decent support (especially if you are premade with good supp) it can be amazing, in this case you should try out Shiina's crit build, Soraka, Janna, Nami, Sona who rushes ardent censer are ideal supports for Kayle. Worths 8/10 with premade, dont play it with random supp.
Support: Meh, i am not sure about that, you wouldnt use E's full potentional. 4/10
Role pros/cons tl;dr:
Top: High reward high risk, recommended builds: AP, AD crit or Hurricane AP feral
Mid: Not as risky as top, might have trouble with some champs, recommended builds: AP
Jungle: We will see what is the next season going to bring, atm recommended builds: AD crit, Hurricane AP feral.
Support: I dont play kayle as support, i am so sorry i dont have much details, possible builds: AP/support items
ADC:High risk high reward, need good supp, recommended builds: AD crit.
Build type explaintion:
AD - High risk high reward, needs more practise, difficult to master.
AP - No risk, averge raward, easy to learn.
On hit builds - Especially OP if fed, can fall behind without being fed.

Some random tips:
- Be careful with ulting your AP carry, cuz zhonya misscommunication is really unpleasant
- If you are detailist you can counter Divine Blessing's animation and deal basic hit and heal yourself at once. Needs good timing.
- Do not use Righteous Fury if it isn't necessary, try to dont last hit with that if the laning phase is going wrong you have to farm with it, there is no other option.
- Maxing Q can be rly strong if you are facing squishy enemy or enemy with armor, try to activate Righteous Fury and throw Reckoning at same time, so as not to be expected.

AP Kayle pros

-Strong late
-Can catch game if there is at least one good carry
-Can help team
-Decent sustain
-Very fast via W

AP Kayle Cons:

-Doesnt ruin tanks unless you go tank eater build
-Team dependant if not fed
-Not best early game
-Ult is not that strong for it's cooldown - 3 sec invulnerability that doesnt block cc and -doesnt clear dots, cant be used while cced
-E got AP nerf, this nerf really hurts
-Q AP nerfed too

AD kayle pros:

-Beast in late game

-More consistent movement speed if built well
-If you hate playing ADC you should try kayle as ADC, she is quite strong with good support.
-Incredibly underrated

AD kayle cons:

-Can be weak early on
-Mana hungry
-Everybody will flame and blame you for every mistake, because these kids are kids who don't understand how much outrageous this build is.

Hybrid kayle: Not viable since passive change