How I feel about it will be greatly affected by how the wording pans out.

Does it remove sleep and stun similar to Tempered Will in addition to negating knockback and draw-in or does it only prevent the application of them?
Does it last until you begin to cast a spell, a spellcast is completed, or the full 10s all the time?

Because if it doesn't remove stun and sleep and only lasts until you begin to cast a spell, while situationally useful will basically mean doing nothing until the thing you want to avoid happens.
On the other hand, if it removes sleep and stun and prevents interruption of one cast but makes you immune to sleep, stun, knockback, and draw-in effects for a full 10s then casters will likely be able to avoid those effects 100% of the time, which would be amazing in fights like levi ex or sophia ex.