Alright, so after playing some matches between Bayonetta, Ken and Richter, I've come to see one thing: how faithfulness to the original source material translates to the character fighting style and how well it translates.
I've played Bayonetta 1 + 2, so to see it translated to Smash is a bit of a jarring situation, considering how combo-complex her series is. Richter, I've only played Bloodstained, if you wanna count a Castlevania game, but can see where his source material lies on and can definitely see the keep away game.
Ken is where I think I excel at the most, considering just how smoothly Street Fighter translates over to Smash, and honestly, where I feel you can have a more consistent combo game than Bayonetta. You're stuck grounded and always facing your opponent, but at the same time, it definitely takes time to truly master his toolset.
Keeping this in mind, I now have another set of "conditions" as to whoever may join the roster, mainly "how well do they implement from their source over to Smash?" We already know of Joker from Persona 5, tons of leaker circles are saying Erdrick from Dragon Quest and two of the most prominent and consistent leakers are pointing to Banjo & Kazooie (though, to keep it fair, these two can of course not happen, never forget "Square rep first"). Having barely playing one of the three, that being Banjo-Kazooie, I do hope that they translate well enough to justify my money spent on the Fighter Pass. I do think, as long as they're unique enough and actually bring something to the table that they can only do, as it's one of the biggest conditions for newcomers, people should welcome in anyone. ...Well, anyone within reason, of course.