|“||There can be only one.||”|
|~ MK description of "There Can Be Only One"|
There Can Be Only One is one of the final upgrades in the Magic Monkey Knowledge Tree, first introduced in Version 3.0. Unlocking this Monkey Knowledge Point unlocks access to the Avatar of the Vengeful Monkey while Monkey Knowledge is active. It requires 9 Points to unlock (requires 8 Points to unlock access to this MK) and additionally requires a one-off purchase of 500.
To unlock There Can Be Only One with as minimal Monkey Knowledge Points spent as possible, purchase "Super Range" and "Heavy Knockback" along with 2 of any other MK above the 4-MK threshold (e.g. "Lingering Magic" and "Hot Magic"), then purchase "Strike Down the False" and purchase 3 other MK (e.g. "Mo' Monkey Money", "Magic Tricks", "Cheaper Doubles"), and then purchase the There Can Be Only One MK.
In order to summon the Avatar of the Vengeful Monkey, have a Sun Temple sacrifice $50,000+ worth of tower types of all four categories (Primary, Military, Magic, Support), and have The Anti-Bloon and Legend of the Night placed out of range of that Sun Temple. If done correctly, the newly emerged True Sun God will absorb both of the two Super Monkeys and form a dark mechanically constructed True Sun God on top of his temple base. Additionally, 2 or more of the formerly golden planes will turn dark purple during the process.