When you think about it, it doesn't matter which SE character we'll get in the end, since they're all really good choices.
Geno, a cult favorite from a cult classic RPG in the Smash and Mario fanbases.
Lara Croft, one of the biggest video game heroines out there
Erdrick/Slime/secondary DQ character, symbol of the biggest landmark JRPG series out there.
Neku, beloved character from a beloved cult classic.
Agnès, one of 8 protagonists from a highly successful Switch game.
Sephiroth, incredibly iconic FF rival/villain that would complement Cloud's inclusion.
Sora, protagonist of Disney's biggest crossover franchise.
So really, it's a win-win situation overall.