Just give it to your warrior. I played a game where I wanted just ice spells for RP reasons, but most of the ice spells suck, so I just reskinned the fire ones as ice, and left the damage as "cold" fire (affected by fire resistance) so as not to affect the game balance.
Obviously ask your DM first, but it's worth noting that Crawford himself says that they literally just don't take damage types into account when designing spells, so changing them shouldn't break anything.
Of course, that's kind absurd, but a slightly more sane take, from the homebrew community, is that damage types are roughly aligned in trios, and you can safely change damage types between the same level or worse without hurting anything.
Those trios being:
bludgeoning/piercing/slashing
cold/fire/poison
acid/lightning/necrotic
force/psychic/radiant
So a cold fireball would be fine, a slashing fireball would be slightly weaker, but a necrotic fireball would be a bit much, and a force fireball is (self-evidently) quite a bit more powerful. I use this myself, to allow casters to be a bit more thematic; at my table, when you learn a spell, you can set it to any equal or lesser damage type and reflavour it however you want. E.g. if someone took fireball, they might say it does piercing damage and flavour it as a blast of needles.
That setup only works if the Bludgeoning/Piercing/Slashing damage is non-magical - practically nothing resists magical B/P/S damage, to the point where I’d put in on the same tier as Force damage, if not higher.
While I agree with the Steel Wind Strike being an insult to put on a wizard and none of the martial classes, this is a bad argument because pretty much every anime swordsman who would pull out a shit like Steel Wind Strike as it is written, is explicit supernatural. I get your sentiment but this is a very flawed, easy to dismantle argument.
That would be a good point if this was an argument, and not just me bellyaching. Also, the supernatural side of anime swordsmen tends to be "They studied the sword so much that they've got these expert abilities" rather than "they spent long enough in the library to unlock these techniques".
To my understanding, I'm not a big anime person.
Nah, a lot of the anime are having their own magic systems - chakra, nen, stands, pacts. It's common to sometimes make mundane look like supernatural (Demon Slayer), but generally if someone teleports most anime would qualify that as a magic use.
If a warrior can withstand the tail weapon of an adult dragon without batting an eye, they should be able to perform Steel Wind Strike just fine.
Besides, nothing in SWS is explicitly supernatural, except for the "teleport next to one of the targets" bit, which could be flavoured as "you move really fast next to them".
That's why I've said "as written". I'm sure this was designed by people who hold the mindsets that doesn't do reflavoring (the recent feat allowing you use deck of cards as spellcasting focus from Book of Many Things is another good example) and also thinks Fighter and Barbarian and Monk are just "guys at the gym". Sadly same sentiments were in WotC since 3rd edition, hence why options martial should get were all given cringy anime names and relegated to new classes and explicit called magic by the text.
I love Steel Wind Strike if only because it gives Bladesingers a group damage option that actually feels Bladesinger-y rather than being forced to throw out Fireballs and the like
Forced. At least it's an option that works unlike Eldritch Knight. Don't get me started on the double strike rules bending people pull with shadow blade and easily end up out damaging the fighter while also having free plate armor AC.
It was the two level dip in paladin on literally any caster that did it for me. Why ever play any other martial when you could do the same thing but with all of the narrative agency of a mage and get 10+ combat revives per day.