Well...Mr. Frosty could try freezing him. Since the robot's made of metal and not some weird, and hard to pronounce alloy he'd be easier to kick down or be shattered by a neat toss of Santa's severed head to Fulgore's middle. BTW he has to be super fast.

Or he could turn the floor into ice, make Fulgore slip, and...I dunno, send jagged shards of ice up or something, to impale Fulgore (a la Rimururu). He is an electrical being, so he'd shortcircuit.

Or Mr. Frosty could try calling in a snowstorm. But then again, he's not Storm.

If all else fails, he could just throw himself at him. But any way you look at it Fulgore would still emerge as the winner, because he's got all those badass abilities on him and melt Mr. Frosty in a blink of an eye.

It's hopeless....TT_TT

Life is short.
Let's all grab a BEER~~~!!!