Arc Flash:
The shinobi would place his hands together, do his hand seals while focusing raiton chakra,
after a brief time (couple rounds?) the shinobthen pulls his hands apart, creating a
large current arc to either block an attack with or touch the opponent with. The block/touching would of course discharge the arc into the enemy doing gloriously excessive damage because cloud deserves it
. Black Lightning:
This ones in the manga/anime, it's an S rank ninjutsu though but it's about the only "high level" raiton ability I could find that wasn't just charging yourself with mad chakra to make your attacks stronger.
Passed down from the third raikage, this ninjutsu would allow the shinobi to bring forth a highly concentrated, black lightning to strike their foes with. Being as it's lightning, and would be high level it would be nice if it would "connect" to any mob in the room (and later on if pk goes in, anyone not currently in your group) doing less damage to the mobs that weren't specifically targeted.
Sorry I didn't take more time to really tie together my presentation, but those are my ideas.
Mune