There was a time when the best use case of Keeper Of The Light was sitting off screen and channeling Illuminate on unwitting opponents who were too slow to react to the whoosh of a max 500 dmg, or they just had the sound off. His role has evolved since then, if not in pubs then in competitive play.
Across all regions at the ongoing Kiev Major Qualifiers, KotL is currently the 7th most contested hero, the 2nd most contested support, and the 4th most banned hero, right below Slardar and Centaur Warrunner. The hero has even warranted a first round ban against select teams, such as Na’Vi and especially Team Liquid.
KoTL is a veritable first round ban against Team Liquid
The change to Chakra Magic in patch 6.86—which buffed its interactions to grant its beneficiaries an increased mana pool and cooldown reduction—solved one of KotL’s largest weaknesses in the lane. He was too passive as a safe lane support, and drafts involving KotL often relegated him as a greedy jungler and later a safety net to counter push.
What the change to Chakra Magic did was make KotL an indirect offensive threat, when paired with the right hero. It was already being abused long before, with the old-school version of Phantom Lancer and Spirit Lance-spam, but the new cooldown reduction and mana pool opened up opportunities with new heroes. So far in the Kiev Major, we’ve seen Nyx+KotL, the return of another familiar pairing with Bristleback in C9’s win over Elements, and then with Wraith King in Vici Gaming’s match against Calvary, where against a tri-lane, End’s WK outfarmed Calvary’s Slark 56 to 53 CS.
Despite this breadth of synergies with KotL and his new Chakra Magic, over a third of pub players place their first skill point in Mana Leak. Two out of the three most popular builds on our page also include placing that first point in Mana Leak. At the same time, pub players are maxing the skill last, leaving that first point in Mana Leak as a value point.
While Mana Leak is an especially powerful skill in the mid to late game—completely negating the potency of heroes like Timbersaw—it’s quite lackluster at level 1. At best, it’s a 1.5 second stun that does no damage and saps the offlaner’s mana. That’s the impact of KotL at level 1 with level 1 Mana Leak. And it won’t be until level 3 before he does anything else. There are better heroes at level 1 who can net kills, and there are even better ones who can protect carries and annoy and zone offlaners.
Na’Vi Biver opting for skill points over talents against team Friends.
Mana Leak is a good enough spell, past level 1, that there have been casesof pros skipping talents to be able to max it as soon as possible. That's also an argument against the strength of his early game talents. All his level 10, 15, and 20 talents target his weakness as a squishy hero. More movespeed, more health, more magic resistance, more armor, less time dead. KotL does have the lowest base Strength out of all the Intelligence heroes, but his Strength gain is average, and he is among the tier of fastest heroes in the game (Enchantress, Luna). Survivability isn't as big of an issue for KotL as Valve's talents make it to be, especially since Aghanim's Scepter, a core item, adds a non-trivial amount of health.
KotL Aghanim’s Scepter upgrade got top ranking in our Scepter Tier List, and rightfully so. It does the same thing as Nightstalker’s upgrade, and while the unobstructed vision was already valuable enough to make it a viable pickup for Nighstalker, KotL version is profoundly better.
The upgrade gives him permanent access to his Spirit Form toolbox and the change to Illuminate makes him a walking, 10 second fountain. His strength was already in his ability to counter-push and clear waves. Scepter opens his offensive capability to support and sustain both his team’s hp and mana pools.
The strength of the item justifies building it first, at the cost of the usual core, support builds. Like Ancient Apparition, it’s usually worth it for a team to lend KotL space in the mid game for him to farm his Scepter.
Some Scepter upgrades unlock new abilities (Nightstalker, Timbersaw, Ogre Magi) or augment existing ones (Storm Spirit, Puck), but KotL’s upgrade does a little bit of everything, and in a way adds synergies with his role. Add onto this his level 25 talent, which adds +200 to both Illuminate’s damage and healing, and KotL becomes one of the most complete support heroes, relevant from beginning to end.
When looking at the current pro meta, one can't help but look at the trend that has gone towards securing strong lanes. Especially the offlane has become much more prominent over the course of the past year and more often than not, pro teams will run some sort of dual lane there. Keeper of the Light provides a flexibility and stability in the draft, that only few other supports can. He's potent in a trilane, both defensively and aggressively, and can even fall back to be a greedy 4 position support that jungles.
In an aggressive dual lane, KotL shines the brightest in the current meta. With Illuminate, he's able to push out the wave constantly, forcing the enemy safelaner to farm underneath his own tower. Illuminate also enables KotL to contest any pull efficiently, or pull the wave himself. It seems only natural for Keeper to be as popular as he is right now, certainly when it comes to pro games.