[MENTION=6671055]horticulture[/MENTION]
Questions:
Would the undead really be empowered?
What would be the area of such outburst?
Would the destruction of the crystal affect us?
Could we create a warding circle to at least lessen the impact on us, if we cannot prevent it's blast to the undead?
Could we create something similar that would channel the energy (maybe into the altar of at least in a line or even blast instead of burst) - so that it empowers only part of the undead (and we would of course choose the side best of us
Roll as appropriate when you consider this initial roll insufficient, apply the roll for at least first two, please, as they are related...