Burmat the Useful

One of the characters in my book is a wizard who is only allowed to stay in Willis because he knows no “battle” spells- i.e. fireballs, fire shield, etc. Now as many DnD players know, sometimes the best offensive spell is a simple utility spell- Grease, Floating Disk, Shatter, Spider Climb, Sepia Snake Sigil, illusions, flying, haste, teleport, etc.

So, I have a 17th level mage who can only have utility spells, and he needs help a silver dragon defeat a much larger red dragon. Which spells should he have on-hand? Keep in mind that the red dragon will be immune to most magical attacks, so it’s really about finding a way to outsmart the dragon.

Thoughts?