first of all golbat does work ive tried it, however seadra doesnt due to poor stats and no recovery etc.
however a first gen noone thought of using:
gloom@evolite
bold, chlorophyll
252 Hp, 108 Def, 148 Sp.def
-leech seed
-moonlight
-giga drain
-sleep powder
the tank of unexpected and eventual doom(if they are not a grass type or get crits too frequently) uses leech seed to drain health(haha jellicent, chansey and blissey) for recovery, moonlight provides mega recovery, espcially in the sun, giga drain prevents taunt baiting and more health regain, finally sleep powder pisses them off alot. these EV's give him 324, 335, 335 which makes him a bit of a tank