Spellwork wasn't exactly Spike's strong point. At least, not if the spells were outside the realm of Herbology, and even then he tried to do stuff manually wherever possible. However he did know a few good duelling spells, courtesy of Jimmy's duelling teaching wayyyy back in his second year.

"Urticate," Spike said, raising his hand, and following the name with a silent 'bamBAM!' in his head. "The stinging hex." He was actually quite good at it too.