A tombstone for M'aiq the Liar, but with visible evidence of something crawling out of the hole.
Maybe have M'Aiq in the grave and when you talk to some random dude in the graveyard he says "M'Aiq cannot die" and he gets out of his grave and you get a storyline?
Anyways: Ruins of an Oblivion gate at the Skyrim - Cyrodiil Border? You know nobody cleaned that mess up!
Oh and I would like to see ONE GUY with a crossbow, gun ,grenade and a helmet that looks like a cliffracers head. PLUS you can't kill him. Would be really annoying.