The mission ruler allows you to make custom triggers that cause events to happen.
Per Xype, mission ruler testing should be done on a local server, in case something breaks. Then, once you have it working, create it on Mythmoor.
NOTE: In case this video play list disappears, Freth has them saved on a hard drive. In that eventuality, just let him know if you want copies.
A mission trigger has to have an advancement of percent complete to trigger. Otherwise it does nothing.