As a reaction, which you use when you make a Will saving throw, you fortify your mind against intrusions. Roll a d4 and add the result to the roll. You can do so after the roll but before any effects of the roll occur.
You can expend 2 additional mana or psi to roll 2d4.
You can expend 4 additional mana or psi to roll 3d4.
You can expend 1 additional mana or psi to trigger the spell when you or one of your allies within 2 meters of you makes a Will saving throw. Until the start of your next turn, you and all allies within 2 meters of you gain a bonus equal to the d4 roll to Will saving throws.