Hi guys,
I am plannig some cleanup on my account and will need to delete some characters.
My question would be that where is the collectiing my mogs for example or achievements ?
so for example if I delete a character which has a specific transmog or achievemnt achieved my the character, will it be removed, or it will be still “saved” on my account ?
Thank you for the info 
Don’t worry, anything account wide will stay unlocked no matter what.
If you really want to part with some characters you’ll loose nothing besides the character and anything you forgot to take out of the non-warbank bank and inventory.
Unless you are near the 65 character limit, don’t delete them. Just place them all at the bottom of your character list and forget about them.
I still have achievements credited to a character that’s been deleted for years, and the only restriction on mogs is class, so you’ll still have them, you just might not be able to use them