>>50886823 In G&S I can reliably drop the goldenrod bimbo's Miltank with a Hypnosis + Curse. Plus if you play with carts, trade it to a spare R/B when it evolves into a Haunter and teach it Thunderbolt + Psychic.
You can then teach Gengar any of the elemental punches for better coverage (Ice Punch most useful for eventual Lance battle).