I think that I've found a way to summon high level monsters such as the Gate Guardian.  Here's what you need:

Monster Reborn
The Chearful Coffin
Level 7 or higher monster card(s)
Ways to get Monster Reborn back (as many times as needed)

All right to start off you need to have these cards in your hand or on the field:  Monster Reborn, The Chearful Coffin, Magician of Faith (a way to get Monster Reborn back), and a level 7 or higher monster (Dark Magician, BEWD, Sagana, Kazijn, Sugin).

You play The Chearful Coffin to discard up to 3 monsters from your hand (discard 2 unless you have Hane-Hane).  Then you play Monster Reborn on one of the monsters,  then Magician of Faith to get Monster Reborn back, then summon the second high level monster from the graveyard.  I think you can summon up to 9 high level monsters if you want.  You just need 3 The Chearful Coffin, and more ways to get Monster Reborn back.

Travis - Sk8brdrocker@aol.com