From Sonic Retro
|Game: Sonic Adventure / Sonic Adventure DX|
|Level: Station Square|
|Fought by: Knuckles|
|Next form: Chaos 4|
Chaos 2 is Knuckles' first boss in Sonic Adventure. After scouring Casinopolis in his search for shards of the Master Emerald, Knuckles spies Dr. Robotnik at the elevators in the Station Square city hotel. Eggman seems to be clutching a shining jewel, which the echidna thinks is a Master Emerald shard. Accordingly, he follows Eggman to the upper floors of the hotel.
During their subsequent unfriendly conversation, Robotnik shows Knuckles that in fact he was carrying a Chaos Emerald rather than a Master shard. However, the Doctor decides to put his former ally to good use - as a guinea pig. Summoning Chaos up through the floor, Robotnik tosses the Emerald to the liquid creature, and sics him on Knuckles.
The boss fight is somewhat similar to Sonic's earlier clash against Chaos 0. The "God of Destruction" shambles around the arena, occasionally lunging at Knuckles with his extendo-arms. In humanoid form he can be injured by a spin jump to the brain, but Chaos 2's more exotic attacks render him temporarily invulnerable. He tries changing into a bouncing ball of water and attempting to crush Knuckles; and also becomes a floating brain surrounded by small droplets when recovering from a hit. The boss can be defeated in 4 hits.
As Chaos melts away, Robotnik has some parting words for Knuckles; he isn't interested in the Master Emerald shards, but Sonic certainly is. This is a blatant lie, but the doubt planted in Knuckles' head plays into Robotnik's hands during Chaos 4.