Use the purple Charge Chameleon Sting, then use the Electric Spark attack (charged or not). To dodge his slash, try jumping up the wall. When he shoots, jump up the wall and try dodging bullets like that. When Sigma jumps up the wall from you, fall when he is on the other side of the wall. Repeat the Charge Chameleon and the Electric Spark attack until Sigma is defeated.
Getting Zero's Buster
Get every upgrade for Mega Man, except for the arm upgrade. Keep playing until you fight Vile the second time in Sigma Palace 3. Defeat him but make sure you do not have the arm upgrade. After you defeat him you will automatically get Zero's Buster from him.
Hadoken Fireball Capsule
To find the hidden capsule to gain the Hadoken Fireball for X you have to get all Heart Tanks, Sub Tanks, Armor Parts (the arm part can be either the one from Dr. Light or the one you get from Zero in Sigma Palace 3) and beat every boss to gain there weapon. Go to Armored Armadillo's Stage and get through the whole stage without taking any damage then at the end dash off the flying platform and land above the entrance to the boss and the capsule will be there.
How to gain Zero's Buster
If you pass over the X-Buster upgrade found in a Dr. Light capsule during the game, you will be rewarded later in the Sigma Fortress by gaining access to Zero's Buster, which is more powerful than the normal X-Buster upgrade. To do this, simply do not enter the Dr. Light capsule containing the X-Buster upgrade, and play the game all the way to the third Sigma level. Upon facing Vile and beating him in a battle, you will speak to Zero and he will give you his buster. This buster shoots a different third level charge shot than Dr. Light's upgrade, which is larger and more powerful.
Megaman X Anime Movie
Beat the game as X.
Play as Vile
Beat the game as X.
Recommended equipment
Note: You must have completed the game to do this. Use the following with Vile.
Arm: Golden Right
Cannon: Necro Burst
Leg: Burning Drive
Unlimited weapon energy for Vile
Successfully complete the game as Vile. Load the cleared saved game to have unlimited energy for your weapons.
Unlock Amored Armadillo
When you get to the first Spike-Tank, wait for it to pass, and enter the room behind its previous location.
Unlock Armored Armadillo's Level
At the second dozer mechaniloid, use the Storm Tornado or Fire Wave to destroy it before it demolishes the wall, then jump up the small tunnel.
Unlock Body Capsule
Storm Eagle's stage beyond blocks that need to be broken with the head upgrade. It is after the thin tower you climb.
Unlock Boomerang Kuwanger
You will clearly see the energy tank after climbing the wall outside to the top. Use the Quick Homesick to grab the Sub-Tank.
Unlock Boomerang Kuwanger's Level
After you have scaled the tower and gained Kuwanger's weapon. Return to the last area of the tower and use it to retrieve it from the outer platform.
Unlock Buster Capsule
Sting Chameleon's stage after climbing up a cliff in the beginning of the level. The dash upgrade is needed for this. Just destroy the green robot.
Unlock Chill Penguin's Level
Venture atop the cave where the igloo-type buildings are located. Use the Fire Wave to destroy the left most building.
Unlock Flame Mammoth
In the room with the Heart Tank, go to the top. Once there, go all the way to the left and jump off the edge, use the head armor part to aquire it.
Unlock Flame Mammoth's Level
After you have finished Chill Penguin, in the area with all the platforms and frozen lava, go to the far right and find it under a long platform.
Unlock Head Capsule
Chill Penguin's stage beyond blocks that need to be kicked by using the leg upgrade. The blocks are found on the right side of a wall in the base.
Unlock Launch Octopus
After the second mini-boss you will see air funnels, use the third one to get to the boat, jump on the moving platform to the right and grab the tank.
Unlock Launch Octopus' Level
Sink the whale battleship and crash through the shutter. Then kill the Utoboros and go into the room on the far right.
Unlock Leg Capsule
Flame Mammoth's stage in a small room which can be accessed by jumping up the left side of a wall after falling through the first long fall.
Unlock Megaman X Anime Movie
Beat the game as X.
Unlock New Title Screen
Beat the game once.
Unlock Spark Mandrill
Go down the first ladder you can, then continue until you reach the pillar. Use your boomerang to grab the Sub Tank.
Unlock Spark Mandrill's Level
After acquiring the Boomerang Cutter, use it to snag the Heart Tank from an unreachable platform near the middle of the level in a top right corner.
Unlock Sting Chameleon's Level
Once Launch Octopus has been defeated, go the this level. Right before the cave, slide down the hole, crush the rocks, and dash over to the platform.
Unlock Sting Chemeleon
Go to X's miniboss area and take Vile's armor through the cave, after the third hole in the ground look for a gap in the ceiling, jump out.
Unlock Storm Eagle
When you reach the area with platforms with fire turrets on them, get to the top, and go in the building on your left. Here you will find the Sub Tank.
Unlock Storm Eagle
Go to the room where X's heart tank is, grab Vile's armor and jump on the platforms all the way to the right. Destroy the boxes in the wall.
Unlock Storm Eagle's Level
After you have acquired the Leg Parts, ride the lifts up the the very top, then dash jump off of the lift to the left, landing on top of a building.