You get... ERASURE

Here's the Master Weapon of Erasure Man...
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You get this weapon from Erasure Man ([link]). Megaman gets to use Erasure Man's staff. When wielding the staff, Megaman can erase any small minions from existence, like Metools. On larger enemies, like sub-bosses and main bosses, Erasure slowly erases skills from opponents, and at the same time, reduce their health, until all that's left is an empty shell.
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Sprites used from Sprites' Inc
Concept from my crazy mind...