Question about Inivs spells, I don't think this is a retread Options

[Deamon_Knight]

I searched but got allot of hits about imp invis v. Sec cameras, but not this.

Say A Mage has a Street Sam brother who like melee combat. They trust each other explicitly, so the mage gives his brother a sustaining focus to sustain imp invis on him, and his brother knows not to loose it (he duct tapes it to his chest to be safe), and the mage keeps on himself. They have a beef with the halloweeners and, safely under the effect of improved invis, decide to knock off some halloweener lieutenants who are hanging out on Their street making trouble. The particularly bloodthirsty Sammie wants to cut the gangers to ribbons with his trusty katana, himself, and asks his brother to hold back watch his hide.

The gangers are largely mooks, and none pierce the illusion as the sammie walks up and casually starts cutting them down, so I have begun to wonder if the surviving gagers should get additional resistance tests (if so, how often?) and a lower TN (if so, how much?) because the illusion is "harder" to believe/sustain. You just can't ignore the evidence, your 3 buddies just got slashed apart, but if you fail the first resistance test, is that it? You are forever fooled by the illusion sans some other magical intervention?

I think I'm going to rule that if someone (who has resisted the illusion) points out to you that you are being fooled by an illusion you get another chance to resist it, and perhaps at a lower TN if the illusion is becoming harder to believe (ie, your 3 friends got chopped open in a way surprisingly reminiscent of an Ork with a Katana).