Rocxidi
The Jim Reaper
If they ban KS but free Aegislash, then they kinda have to consider unbanning Blaze Blaziken. And that to me is the biggest reason I'm against the idea.
No. Smogon has made their desire to avoid complex bans clear. This is just a special case where Haunter decided that King's Shield could be the only exception. Makes sense because King's Shield created uncompetitive coin flip scenarios that depended purely on luck, while its typing and pseudo 720 BST are things you can actually handle. As I had stated, Aegislash King's Shield is broken.
Also, unbanning Blaze Blaziken can only be done by banning Speed Boost. There go Scolipede and friends. Same for Greninja.
And finally, Darkrai and Shaymin aren't ubers just because of Dark Void and Seed Flare respectively. Darkrai is fast and has a great movepool, while Shaymin remains fast and is still able to flinch you with Air Slash.