Vampiric Abilities [2K3]

Havent been on this site in years but I recently got a huge inspiration for a game.

anyway I have a person who I want to use blood magic. He basically saps a charactor of something and it makes him better. I set up a bunch of conditions for this. I set a condition for them to have less power and a condition for him to have more power.

my problem is this, I don't know how to use varables very well and I really don't know if this is possible at all. I cant single out a skill to turn on a switch AND do something. I also have no idea how to use the Change Condition event thing to give a charactor of your choosing.(like giving a choice window event and whatever they choose gets a condition)

So in short, Is this even possible? If so, how do I go about doing it.

I think this *might* be possible.
But since I'm not a 2k3 user, I don't have the slightest clue.
Good luck though. 

So I started messing with stuff and I found out that I can set a bunch of common events where if a charactor is infected with the status Bludcrse then I can specifically give Bludgane to my character. considering I only have one character that will be able to cause these conditions, this seems like a good method of doing it.

Here is the issue though, my game consists of two worlds. In one world this character sucks abilities from other members to power him up. In another world character A is linked to Character B. B can sap his own abilities to give party members abilities.

I can use the same common events strategy to reverse the process and that is fine. However, can I use variables somehow to just go "If any character other than this one is infected with bludcrse then this character will get bludgane"

??