7:29 AM
@trogdor I think there is a misunderstanding, sorry. What I meant is that if another wizard casted the Spell of Mastery, it is an automatic win for him - you don't get banished, you straight lose.
That said, I don't remember if you could cast any other spell outside the Spell of Return when you were banished but I doubt it.
I seem to remember that as soon as you were banished, you were automatically given the opportunity to start casting the Spell of Return. If you refused that option (either because you just wanted to forfeit the match since you didn't have any hope to win at that point or because you lacked the resource) it was an immediate loss.
So basically either you begun casting the Spell of Return as soon as you were banished or you wouldn't get another opportunity.
Since you could NOT cast two spell at the same time... that mean you couldn't cast the Spell of Mastery while banished.
But... take this with a grain of salt, there is a chance I am misremembering things
