for normal pokemon its head to head with glacion and alolan ninetales (ice is my favorite element in everything-) and for legendaries, unpopular opinion but articuno 100% honorable mention goes to meloetta! i LOVED that event with the relic song and the type change is really sick! Edit: ...
Crown Tundra also brings in Regieleki and Regidrago, but thanks to its unique approach of legendaries, any of the following could reasonably pop up in aPokemon LegendsGalar’s endgame as well: Raikou, Entei, Suicune, Lugia, Ho-Oh, Regirock, Regice, Registeel, Latias, Latios,Kyogre, Groudo...
Most pseudo-legendaries adore this overall. Dragonite and Salamence get physical STAB that's not hidden power, and can boost up with Dragon Dance. Adding on to the fun Fire Blast is physical too, meaning that after a boost it'll be pretty hard to actually stop them. Tyranitar meanwhile...