Wily 1 Boss - Atetemino

From The Compendium

HP: 40

Damage Chart:

Damage Values:

Note that optimizing this fight requires destroying all four components of the boss as quickly as possible, as the next set will begin to spawn only after all elements of the previous set are gone. 

Your speed and other factors when hitting the boss door to Atetemino will determine how far Mega Man walks into the room. The further left you are, the tighter the window for getting early hit. To do the early hit, place the right side of Mega Man’s helmet on the red line, and mash square while holding up.

Notes

Nobody knows how to pronounce its name

Remember you can hold up to kick a ball at a steeper angle than normal

As mentioned above, try to get the early hit. You likely need to move slightly to the left before quickly kicking a ball up at him. Atetemino always starts in "the third" slot (center-right).

Find places where you feel comfortable kicking balls into each slot. As mentioned you want to destroy things quickly anyway. You should be kicking balls into openings before he spawns each cycle to help this. This includes destroying the fake Atetemino bomb on the next to last cycle. You can collect weapon energy from the boxes, so feel free to spam shots.

The above red line image is good for hitting the "third" slot. The mirror of that from the right side kicking left can hit the "second"/center-left slot. Both edges can be hit with up-kicks from the center.

For the last hit, try to be kicking from the center and hope for an early hit. Being centered for the kill as usual gives a quicker teleport out of the stage.