Talk:Kayle/Strategy/@comment-5436279-20120829230442/@comment-24.7.187.204-20121231023209

Her Q (Reckoning) slows an opponent, and also amplifies any damage Kayle does to that opponent.

Exhaust does not do any damage, so there is nothing to amplify;  Ignite does do damage, so if Kayle casts Ignite on the same opponent that she had previously cast Reckoning on than Ignite will have increased damage dealt.

Slows or Movement speed debuffs do stack, but not in the way that you think. This is explained in detail in the MOVEMENT SPEED page under the SLOW STACKING heading.