[Illuminated One]

You mean magic duel I guess?

S1 is enough to protect from Mindhunts.

Magic Duel however works like this iirc:

Enemy base Astral (boosters are not counted) + d6 >= Your base Astral + d6 => you're dead

So even a S5 mage can die against a S1 mage. The chance is about 8%. Against a S2 mage the chance is about 16%.