[SixOfSpades]

Summons are a decent delaying tactic against Gauths, but not against Beholders. Beholders have infinite castings of Death Spell, which is instant death for any Summoned creature, Death Warded or not, Magic Resistant or not.

Fret not, however, your Mage will save you!

1) You can have more than 1 Spell Immunity active at the same time, and Spell Shield grants immunity to Anti-Magic Rays

2) There's a Level 4 spell that's almost as useful as the Cloak/Shield of Cheese (in this situation), although if you're in Chapter 5, you'll need a Level 5 spell too.