I hate this stupid X monster thing! It's so frustrating!! D:<
Getting to the tunnel: Use the Bubbler to clear out enemies ahead. Charge up a full one and run past the trigger zone, then fire at everything ahead.
Once all the enemies are dead, jump onto the types back and forth until it stops. Switch to the Blade.
Jump in the middle, fire a L3 Blade upwards, then immediately press Q. Switch to Missiles, hit Q again, fire as much as you can at one of the purple X shooters. When the Blade's radius effect runs out, use Q to switch quickly to it, fire it and then back to Missiles.
When the middle closes, switch to the Blade and back off. Fire the radius blasts to combat groups of the purple shots firing at you, and wait it out until the machine stops. Repeat the above until the four X shooters are dead.
When the middle opens again, keep firing Blade radius blasts to keep the homing missiles away and other shots. If you run out of Missiles, switch to Polar Star, Snake or Machine Gun. Switch through the Blade quickly to avoid getting hit as you'll lose the level 3 version. I did this boss on 3HP so getting hit meant death, so I don't know what might work - try just using the L2/L1 Blade as it does much more damage than the others weapons at close range, but without the protection radius.
Poll