The early game for KOTL, besides your usual support duties, is all based on your Illuminate and Chakra Magic. You want to use the two spells to dominate your lane and provide a good start to the farmer in your lane. If you feel that your lane is secured already you can move to the jungle, make some stacks and farm them.
Anti-Push: Illuminate is arguably the strongest anti-push spell in the game as its sheer damage potential and the ability to use it from a very long distance (without committing to a fight) can make pushing practically impossible, especially in the early and mid stages.
Team Fight Control: KotL's Will-o-Wisp is a very powerful team fight control spell. With Refresher, it could become impossible to deal with. Blinding Light also shouldn't be underestimated - it's especially powerful at messing up the initiation follow-up of the enemy team.
Magical AoE Damage: Illuminate is not only a defensive spell - a well-aimed blast can turn a fight around, especially if it hits multiple targets. It is hard to land as it takes a lot of time to cast; however, in cluttered team fights and in chokepoints, it can be devastating.
Fast Farmer: For a support, KOTL is a very fast farmer because he has the opportunity to clear instantly very big creep waves (and stacked camps) with Illuminate. This means that if there is space on the map for him to get creeps, which the cores aren’t getting, he can acquire significant items and become a danger to the enemy team. He is also one of the very few supports that can effectively farm the jungle.
Fast Movement: As all mounted heroes, KOTL has a very high movement speed (335). This means he loses less time in traveling between destinations, and that he can possibly run away from unwanted engagements (if he is not disabled), which is an important trait given his overall bad survivability.
Unlimited Mana: It is always a good thing to be able to not worry about your own mana and use your spells often, which is the case with KOTL. However, Chakra Magic shines the most when you combined with mana dependent heroes as it can make their whole game much easier and increase their impact.