Dark Ronin are ancient suits of armor which have been animated by the Maelstrom.
Long ago, brave warriors faced the forces of evil on Mantis Rock. They have since presumably passed away, but their armor was placed on ronin statues to populate Forbidden Valley in memory of the brave warriors. However, the Darkitect came to Forbidden Valley and used his Maelstrom powers to bring the suits of armor to life as Dark Ronin. The Dark Ronin whispered to the Darkitect, telling him how to enter the dreams of sleeping Ninjas, ultimately leading to the creation of the Maelstrom Dragons.
In Forbidden Valley, Dark Ronin populate Mantis Rock, Cavalry Hill, and Forbidden Passage in their inanimate statue forms. If players approach a ronin statue, the statue will crumble and reveal a Dark Ronin, which will proceed to attack the player who awoke it. The ronin statue has 3 Life and, if players act quickly, can be smashed before the Dark Ronin awakes, preventing the Stromling from spawning. If players fail to smash the statue, they must battle the awakened Dark Ronin, which has 12 Life and will attack quickly with its katana. Although dangerous in large numbers, Dark Ronin are also popular among players for farming due to the Dark Ronin's high loot drop rate.
As part of the Great Tree Ninjas' training, Smashmaster Foom sends players to prove themselves by smashing ten Dark Ronin. Bill Shido teaches players about the tactic of smashing ronin statues before the Dark Ronin awake, then makes a bet with players to smash twenty of the ronin statues.
Dark Ronin can also be found spawning without statues outside the Paradox Refinery, where they try unsuccessfully to attack the Paradox laboratory. When the Dark Ronin attempt to approach the Paradox Refinery, they are quickly dispatched by Brick Fury. However, the Dark Ronin will attack any player who passes beyond Brick Fury's firing range, serving as guardians for the entrance to the Maelstrom Valley.
In the Forbidden Valley Dragon Battle, Dark Ronin are spawned in pillars of fire created by an unnamed Maelstrom Dragon flying around the valley. These Dark Ronin can be quickly dispatched by players, due to having only 4 Life in this instance. The main purpose of these Dark Ronin is to supply players with power-ups, since these Dark Ronin drop no loot but lots of Life, Armor, and Imagination power-ups.
Katana Swipe: The Dark Ronin quickly swings its blade forward, dealing 2 damage on contact.
Blade Combo: The Dark Ronin makes three swipes with its katana in rapid succession. Each swipe deals 2 damage, with a maximum of 6 damage.
In beta testing, ronin statues appeared in much larger numbers in Mantis Rock, causing Dark Ronin to spawn much more frequently. Until the Frostivus update, Dark Ronin had different sound effects and a lower-pitched voice.
When the fourth Maelstrom Dragon of Maelstrom Valley was first given the ability to summon enemies into battle, its fire pillars spawned Stromlings. However, despite their appearance and animations, the Stromlings were identified as Dark Ronin and behaved similarly to the Dark Ronin in the released version of the game, implying that they were originally intended as Dark Ronin.
"Ronin" is the Japanese word for "masterless samurai". Smashmaster Foom suggests that this was an accurate description of the ancient warriors, claiming that the "Ronin once knew no commands" before the Darkitect possessed their armor.
Maelstrom Horsemen appear to be Dark Ronin mounted on skeletal horses. This is reflected by an early piece of concept art for Maelstrom Horsemen, in which players were intended to dismount the horseman, which was used as a placeholder for Dark Ronin artwork in the Passport during beta testing.
The segment of the Dark Ronin statue's spear which connects the shaft to the blade is the same design used on a Stromling's blade arm.
Non-possessed ronin statues appear frequently as a design motif throughout Forbidden Valley. For example, part of the statue can be seen on the gate to Cavalry Hill and on Maelstrom Turrets.
During the November 22, 2011 Nexus Tower party hosted by Shival, numerous unused Named Enemies were spawned, including NAMED Dark Ronin. NAMED Dark Ronin was later respawned at a Nimbus Plaza event.