>>40585253With galvantula you get better speed, and a better OHKO (for ingame) with Thunder, problem is that anything that resist thunder is probably not going to die to a bugbuzz/energy ball, and Galvantula is pretty frail.
Eelectross has higher defenses and offenses but lower speed, and in my experience is not that good at dealing damage, you need some good EVs for that. but boy he does get a ton of coverage like flamethrower and grass knot (and elemental punches in BW2).
