Super Smash Bros. Ultimate

Sephiroth is a pretty fine addition tbh
Fine as individual isn't a garuntee for fit, I think.

Like I love ice cream but I don't pick it for dinner.

Sephiroth is from Final Fantasy 7. To put things short, Final Fantasy 7 played a huge role in popularizing JRPGs in the west, and he's the main villain of the game. He's very iconic and well-known. Just look Final Fantasy 7 up on Wikipedia, it'll give you information you need and why he's popular and put into Smash Bros.
I think the arguable part is denying other Square contents are iconic enough for their own history. And to FF fans in general they'd want something else to be presented to show different universes of same series.

Sephiroth is chosen more because of his personal charm in games that garuntees the income for a DLC, while NIntendo choose to ignore game crossover matters in this one. But like the Byleth case, I think an actual smart presenter would just say "we would try to push unexpected additions to wow you" which is much less specific than "we want to expand the game worlds in Smash".

The really shadowed and robberd candidate is Chocobo, who could had been legally counted a seperate IP character, although we know he wouldn't make as much money as Sephiroth tbh. I think this would be like SNK announce another Fatal Fury character despite KoF have tons of candidates around.
 
i know some people are mad because "NOOOOOOO SWORD BAD!!!!", but sephiroth practically saved final fantasy presentation in smash. now we can have more than two songs, and actual spirits.

its definitely gonna introduce some people to final fantasy, which smash 4 SHOULDVE DONE when they put in cloud, but the lack of final fantasy content didnt really make younger people wanna play final fantasy.

plus sephiroth is an iconic villain so theres that
 
its definitely gonna introduce some people to final fantasy, which smash 4 SHOULDVE DONE when they put in cloud, but the lack of final fantasy content didnt really make younger people wanna play final fantasy.
In the case of Smash bros it isn't obliged to introduce more of 3rd party series, as far as I know. And people who bought Smash 5 were already aware of Final Fantasy since it's not unpresented like Octopath.

On the other hand not having other contents is just the companies' issues. If they cannot be open enough, more DLCs would still not help.
 
are you the person who didn't know what DOOM was?

or am I confusing you for someone else because none of the kids on this forum know any games that aren't Mario or Kirby.
I don't recall saying anything about DOOM, but I don't know anything about it.

Well, I know a lot about Mario, Kirby, Smash, and a few random games. (Miitopia, BotW, etc.)