they're, already from a pokemon game ASDJSDJFL THEY HAVE WHOLE TEAMS. i'm Horrible at assigning these but... we associate fern (reincarnation au specifically) with alolan ninetales if not his signature pokemon, froslass (canonverse). the fact that he lives in a snowy area and likes the cold + his name is fern gives him a natural ice-grass typing, and i think snover/abomasnow (the only dual ice and grass types) also would fit him rather well...! funnily enough he's also afraid of fire (there is a lore reason for this) which fits eerily well with his types. as for jax, he's absolutely a flying type but he's not so clear-cut for me... his signature pokemon is staraptor, though in terms of reflecting him in his development, i believe he would have only 'evolved' into staraptor at the very end of the game's storyline. i can also see him as the bagon-shelgon-salamence line (how funny that he also has a salamence in his party!) because of its determination to fly and (gestures awkwardly) his character development feels a little similar... yes. yes those are my thoughts