Mega Man X2: Serges Fight 2, No Upgrades & X Buster Only

While the second Serges battle is usually no problem for people when they exploit his weaknesses (Silk Shot or Giga Crush then Sonic Slicer), it's one of the more challenging bosses of the game when you're doing a run with just the X Buster and no upgrades or tanks. Note the care taken to destroy the second and fourth cannons at the same time.