D&D 3.5 Grafts

[DeadAggressor]

In the current campaign I'm playing in one of my buddies is playing a Demon Summoner/Binder type class. I was wondering if I got him to bind a Sibriex and had it cast its 3/d grafts on me, how do I resist wanting to do evil acts from the fiendish grafts? I'm a CN Strongheart Halfing.

[sreservoir]

you ensure you can make the will save. repeatedly.

use a ring of the diamond mind for moment of perfect mind, and pump your concentration enough not to fail a save on a 1.

as failsafes, pump your will save enough not to fail on a 2.

have a (uncharged, preferably -- is cheaper) luck blade. have a mantle of second chances. have an amulet of fortune prevailing. possibly use planar touchstone to use the catalogues of enlightenment base ability on the luck domain. that gives you four rerolls if necessary.

[DeadAggressor]

What is the will save based on? What would be the DC?

Edit: What a Rogue's or Shadow Dancer's Slipper Mind class ability give me a second chance to pass the save?

[Alleine]

The will save is a flat DC 15, every day. Fiendish grafts also have the effect of nuking all of you charisma based checks against non-evil NPCs. I hope you aren't the party face.

As for Slippery Mind, no it would not give you a second chance. It explicitly states enchantment spell or effect, and the will save does not call itself out as being an enchantment effect.