Re: Help me with my Champions plot
Or, Gilgamesh did indeed find the secret, and used it. Unfortunately, a latter adventure (which was not recorded) causes him to lose his memory. Since then, he has been wandering the Earth. While he is immortal, he has no recollection of his past life (indeed, his current state could be that of a derelict, unable to recall yesterday, let alone the days of Uruk.)
Using the seal has two immediate results: one, it opens up the tomb of Enkidu, and he is set free. Two, Gilgamesh recalls who (and what) he is, and he wants his property back. Now. He's not interested in the excuses of "it belongs in a museum" or "we're the good guys" - all he knows is that someone else has what's his, and he wants it back.
So, you have Demon and Viper fighting over the seal, with heroes intervening, until someone actually uses it. At which point, you now have Demon v Viper v heroes v Gilgamesh, oh, and by the way, a wild man is rampaging through some town, tearing up cars and babbling in a long-forgotten tongue.