\m/ The metal sign is actually a bucket sign. \m/
Bucketbots, the ultimate rebels with Big B in the lead, we wear the horns sign on our heads proudly INVERTED.
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I don't know Buckethead's beliefs; even as atheist, it doesn't matter, since horns signs and inverted crosses defy god; nothing is cooler than defying the devil, also, as Buckethead defies metal music, turning everything on its head.

Taking the whole hand into perspective, facing the knuckles or palm, most evident in everyone's face topping everything, the bucket shapes metal's symbol crown, with Buckethead as King, the G.O.A.T.

The sign becomes most symbolic because Buckethead's benefit is uniting everyone in music, BucketheadLand's music.