>>37426516>Ice BeamThe general "rule" is that fire mons don't learn strong and accurate ice attacks and ice mons don't learn strong and accurate fire attacks.
There ARE notable exceptions of ice mons learning fire moves (kyurem learns sunny day, kyurem-white learns fusion flare, rotom-frost learns will-o-wisp, arceus-ice learns fire moves, castform learns fire moves, froslass learns will-o-wisp, around 6 or 7 ice mons learn sunny day, etc.) and fire mons learning ice moves (victini learns glaciate, a-marowak learns blizzard, around 4 or 5 fire mons learn haze, volcanion learns mist, oricorio learns icy wind, etc.), but most of these exceptions are either completely useless moves, or moves learned through some sort of convoluted form change; so far they've never made a fire type that gets ice fang/punch/beam, or an ice type that gets fire fang/punch/blast. I'm not saying I support this (I'd love if they broke out of this autism for some variety), but I think it's likely they're not gonna do it until they eventually have to confront the idea of making a fire/ice mon.
That said, I'd absolutely love if delphox could lern Blizzard. The idea of a fire mage that fucks with move distribution because it fits its theme is cool to me. If gamefreak weren't so bent on their moveset rules, they should give it Blizzard and Thunder (besides everything else you said except sludge bomb, probably).