Since his damage output and movement speed are both 2/3 of that of the original 400% Teacher Bun Bun encountered in Moon, in addition to having a second trait, Bun Bun Black is actually less threatening than Teacher Bun Bun under most circumstances.
The True form of Shaman Cat works effectively against this enemy and all of the alternate forms (Excluding relic and mecha bun.)
"LOVE TAKES YOU TO HEAVEN #LOVE"
That's what he says when he hits people. Some say you can go see the other world when he hits you... Sorry, no valid source.
Love will send thee to heaven! And the other world is visible once the dangerous teacher comes to hit you suddenly with love. Unaccountable.