While casting a spell with your left hand with a weapon equipped in your right, hold attack to block with your right hand. You will only block if you are casting, and can still attack freely with your right hand weapon.
Requirements
This mod does not have any known dependencies other than the base game.
Permissions and credits
Credits and distribution permission
Other user's assetsAll the assets in this file belong to the author, or are from free-to-use modder's resources
Upload permissionYou can upload this file to other sites but you must credit me as the creator of the file
Modification permissionYou are allowed to modify my files and release bug fixes or improve on the features without permission from or credit to me
Conversion permissionYou can convert this file to work with other games as long as you credit me as the creator of the file
Asset use permissionYou are allowed to use the assets in this file without permission or crediting me
Asset use permission in mods/files that are being soldYou are not allowed to use assets from this file in any mods/files that are being sold, for money, on Steam Workshop or other platforms
Asset use permission in mods/files that earn donation pointsYou are allowed to earn Donation Points for your mods if they use my assets
Author notes
Do whatever with it. Just credit Zartar and JZBai
File credits
Zartar for Character Behaviors Enhanced (https://www.nexusmods.com/skyrim/mods/90552), JZBai for his unofficial Character Behaviors Enhanced patch (https://www.nexusmods.com/skyrimspecialedition/mods/40417?tab=description)
Donation Points system
This mod is opted-in to receive Donation Points
A feature from Zartar's Character Behaviors Enhanced that I converted to a standalone mod. No behavior files or scripting. It's a single .esp that should be compatible with most combat and animation overhauls, old and new. Works in 1st and 3rd person, and with NPCs too.
Known issue: If you hold attack (block, in this case) for too long while casting your character will eventually perform a right hand power attack.