Akysos

Yes depending on what you get from the mysterious egg you can work from there. Noivern's main asset is its speed, but to be really competitive you need to have a good nature such as timid, rash boosts special attack but lowers special defense making him weaker defensively. Noivern is still kind of nice statistically speaking and in terms of movesets. In case you are wanting to keep him but make him more competitive, breed him and get a timid with the following moveset: dragon pulse/hurricane/boomburst/flamethrower (no need to breed moves just the nature). Then you already have two big fast special sweepers with roserade and gardevoir, you could add porygon z (rip link stones) or chandelure or misdreavus; all of them would be better with a modest nature.

You have a pretty well balanced team, if you have a bit of time to work on leveling up, breeding egg moves or even go down to nature breeding you could make one or two changes to get even more balanced. I would say that the main weakness of your team is your sharpedo, you could replace it by: Lapras (modest) with ice beam/surf then you have a choice waiting for thunderbolt to be available, either use hydratation and put rain dance/rest or go for more attacking moves such as hidden power and dragon pulse (egg move) Milotic (modest) even if you can only have restricted movesets so far with only a few interesting moves such as surf, hidden power and recover (maybe add dragon pulse by breeding feebas first) You could also use a nice physical water pokemon such as an adamant Feraligatr with sheer force and as a moveset such as Waterfall/superpower/crunch/ice punch (breeding move) That could be it to replace your sharpedo, for noivern what style of replacement are you looking for ? Fast special sweeper or just the dragon type ?

You could drop Linoone for a water/grass type pokemon, it will be useful later in the game.

You can get quite a few high level Rock and Ice pokemons in the moutains to help you with Ciel (Spheal and sturdy Boldore are easy to catch). A sturdy rock type placing stealth rock and eventually attacking if togekiss boosts itself/misses at the first turn would help you a lot. Ampharos with discharge/powergem moveset would do a lot of damage as well, if you need to xp farm one pokemon I would go for him. You can learn rock tomb to most of your physical pokemons as well.