About time I jumped into this thread! I'm going crazy in this direct gap waiting for any kind of confirmation. I've been too absorbed in the fact that it's kinda make or break for Isaac in Smash this time; clearly he's either in or he's not, but the latter seems unfathomable given his circumstances as a first party character long overdue a proper invitation to Smash.
Anyway, I put together a little Wishlist on GS assets I'd love to see in Ultimate. I didn't delve too much into move sets since I change my mind constantly. I fully trust Sakurai and his team to pull out a really fun, representative moveset. Personally I'm in the vanilla Venus adept camp, and I'm not keen on using Djinn as a gimmick, although I'd like to see them in his animations somehow.
So, my wishlist.
Fighter: Isaac - I imagine him as a medium range fighter due to the psynergy at his disposal; throwing earth and using catch for his grab. I could see him as a mostly grounded character, not great in the air but good at edge guarding with Move or Spire if he has something like that. I think his B would be his familiar Move ability, pushing outwards like his AT. I'd like to see Ragnarok or Titan Blade as his Final smash, since it can just crash into the stage. As much as I love Judgement it's far and beyond the power of most final smashes.
Semi Clone: Felix (Not an echo) - Sakurai already mentioned why Isabelle was a unique character, its because she doesn't match Villager's size. This is far more the case for Felix and Isaac. I picture Felix being like an adult Link to Isaac's young Link in this case, he'd be heavier and would hit harder, possibly use different abilities to Isaac so we get even more variety. I even think his Move ability could push inwards, to bring people closer so he can wail away with his stronger physical attacks. This could be a good way to distinguish the two better. Also would love to see Odyssey as his final smash to be similar to Isaac's, only horizontal.
Note: An echo would be fine, they'd just have to make them the same height which might feel a bit odd. Happy either way.
Stage: Venus Lighthouse - A prominent location in the series as both the conclusion to Golden Sun and beginning of The Lost Age. I think it's the most iconic place in Wayard that represents the series. Plus they could have a hazard of the Lighthouse splitting apart. I would even go as far as wanting Saturos and Menardi as stage hazards, casting eruptions you have to dodge.
Assist Trophy: Jenna - Chosen because she means the most to both Isaac and Felix, and is an important character in both arcs. Obviously any character or Djinni would be suitable but I imagine there's only going to be one trophy so Jenna was my top choice. I can see her casting some Mars synergy across the stage. She could end up doing a lot of AoE to the point where it'd be beneficial to K.O. her fast. Serpent Fume is quite iconic for her in my mind.
Item: Spark Shuriken - This one was really hard to think of because I'm not all that familiar with the items in the series unless they're special weapons. There also aren't that many items in the games overall that could bring something unique. This was my best find because you can shoot lightning projectiles. That's kinda cool.
Music: Isaac Battle / Saturos Battle / Saturos & Menardi / Jenna Battle / Venus Lighthouse / Overworld - Most of these should go without saying, and there's definitely more I'd be happy to see added.
Sakurai would have to be very generous to provide everything on this list, and I would be ecstatic if he did. However, even the bare minimal of having Isaac in the base roster would make me very happy, and satisfy a 16 year old wish.