In an October 2 post, Valve announced that Rat King is available to play in Deadlock. The hero was introduced through Scrap Grenade, Rat Swarm and defensive Royal Pestments.
According to the team's description, Rat King can lead an attack under the Ratannia banner while supporting his allies. This is an announcement about the availability of the hero, and not a detailed analysis of the optimal build. Damage and cooldown numbers should be checked against subsequent patch notes: a separate balance adjustment was published on October 5th. We do not transfer the promise of the next hero from the old schedule to the current date without new confirmation.