Eh, question is... Why Hades?
Then I can say I prefer Viridi than Hades as well.... Even though they have fairly same chance....
It was an example. Besides, Hades has better chances than Viridi due to the simple fact that he has some moveset potential.
All we see Viridi do is summon monsters and throw giant nukes, we
never see her fight.
The former would make for a good summoner kind of playstyle, I'll admit, but both Medusa and Hades can do that too.
But again, this was nothing more than an example to do expand on my point.
And really? Sure, character's own merit and ability is a good for potential speculation... But when has the Smash Bros roster pick always been fair? We haven't got Ridley, we haven't get King K Rool... And other highly fan requested characters that I do agree that they really should be in...
It's never been fair, I agree.
But by saying that, you're also saying there's a chance Bandana Dee
won't get in, which clashes with your "Bandana Dee will show up because Sakurai created Kirby" argument.
Bandana Dee had his chances in Smash 4 because of Return to Dream Land and didn't make it in. And we know Sakurai noticed that game because that's where Kirby's Final Smash in that game comes from. So he likely noticed Bandana Dee and ignored him for this game.
In fact, anything that's from a Kirby game that Sakurai didn't make tends to get the short end of the stick, being either a collectible, a song or, in the case of the Ultra Sword, just a Final Smash.
While Bandana Dee
did appear in Kirby Super Star, a game most Kirby stages come from, there's a more major character than a mere NPC in a minigame Sakurai could take assuming Sakubias was the only thing that mattered; Marx.
But sorry to say this but from seeing the past roster, I have say that creator/series bias is there....
Yes, but it's not the only thing that's there.
For example, he wasn't certain about a sixth Fire Emblem character in Smash 4, thinking it was too much, but he did it anyway.
If creator bias was the only thing driving his reasoning, Corrin would've never made it in Smash.
I'm not saying there's zero creator bias in Smash rosters, because every creator will have some bias. I'm saying it's not the only thing there is in Sakurai's reasonings.