I have looked at alot of the xml code and how the devs did things. It looks like you can use <Prereq> using AND by simply adding another <Prereq> tag, but it doesn't seem you can do much else. Namely I am wanting to do some OR operands. Deciding that is not possible, I thought I would create a new player tag and set it to 1 in the two places I want to OR with. But no matter how I try, I can not get it to work like I want. To explain the details, I want the Summoner OR Summon I to set a flag that unlocks the Summon Shadow Warg. I tried to create a new ability called SummonFlag and set an Attribute and/or StrVal to 1 but it never worked.
Would anyone want to give sort of a tutorial on how this could be done and explain how the tags work so we could do it ourselves next time?