IMO Kayle isnt that good for TT.
Most team compositions are something like this: tanky dps + jungler + AP burster
Kayle is a hybrid DPS ranged carry. She is too squishy and vulnerable to disables. She has no jump skills and her ultimate isnt that good enough. Ezreal is far superior as a ranged Hybrid DPS for TT.
In order to play with a Kayle on your team, your composition should be something like: Kayle + CC heavy tank (alistar, cho gath or maybe singed) + (not so tanky) Jungler. Since Kayle is too fragile, the main role of your tank will be to save Kayle's ass.
DPS carrys on TT must be tough enough in order to have 15 sec fights at lvl 18. Mundo, Udyr, Olaf, Xin Zhao are good examples. Kayle is just too fragile (even with ulti). 1 Fed Udyr can beat 2 fed Kayles (or maybe 3).