I'll suggest this as a possible aternative. Thanks
To clarify the mark in question is the paladins divine challenge, which in our game has mainly been used to damage targets that ignore the paladin.
I was informed they would "be in no more then 3-4 encounters". Since thats about a one to one...
I have been running a game for a couple of months for a small group, and have just passed it over to one of my players. He is a first time DM and we discuss our campaigns and rules and such on a regular basis.
He recently told me that one of the key monsters he created has immunity to marks from...