Aegis was unbanned because King's Shield helps check a lot of the meta, especially the physical attackers like jirachi/talonflame which run rampant
This argument was brought forward ever time but its honestly not true.
When you evaluate a pokemon you have to evaluate a plethora of different key factors attributed to said pokemon. Aegislash is a pokemon that is difficult to deem directly broken. In OU its not too powerful, it's has a lot of power behind it but not enough to be seen as overwhelming. It's defensive but lacks recovery, but thats generally a diminished argument as it has a fantastic offensive and defensive typing. It has no counters, no pokemon can deal with all of its sets.
But that is OU. In Linked Aegislash is exponentially better. King shield + Protect was banned, reasoning could be seen above. However, it can still use King shield, and that alone is uncompetitive. Having King Shield makes physical attacks severly less viable. And it's almost always in Aegislash's favour. You either risk getting minus two attack or you're leaving yourself voulnerable by going for a status move too two stab 252 Modest attacks, or unresisted coverage hitting hard on both sides in Sacred sword + Shadow sneak. It still has immense bulk and with all the physicals attacks running around you can drop too 25% attack.
You can, of course, boost while attacking an hilariously broken aspect of this metagame, but it boosts Aegislashes power and prescence to astronomical levels.
Not only that but its bulk, power and typing allow it to effectively diminish fighting, bug, grass, ice, rock, steel, normal and flying types. Just by allowing Aegislash into the metagame you effetively discourage any opponent and yourself from running these types, for coverage or stab.
Now Talonflame. Talonflame is one of those pokemon that's good in most metagames. Its unique ability allows it to work effectively in any metagame(most). In Linked its no exception. Linking Brave bird + Aerial ace essentially gives Talonflame Parentsl Bond priority stab... Wow. That's breath taking. For comparisant the only Bug types that live banded Parental bond Brave bird is Shuckle and Bulky Mega Scizor. I think, I only calced those and Shuckle take 70-80%.
Isn't that awful? If Aegislash + Talonflame stay in the metagame all Bug types are diminished in their viability. I have yet to calculate fighting and grass types, but if I were to go out on a limb im going to say very, very few would live a hit.
But that's not it. Team building for offence is neigh impossible without adding Aeigslash, Clefable, Talonflame and Manaphy. Though Manaphy & Clefable is easier to handle. You're so limited and there's next too no reason not to run these pokemon.
They also restricts what you can use, like Fusion x2 Victini and Felt stinger Beedrill, both innovative and creative sets. I'd love to see the real potential Linked has, 2x Victini is one of the coolest pokemon in linked imo imo.
That's all for now