Help me build a BBEG!!

[Spectre3541]

So for the campaign I'm running in the coming months I'm having trouble actually building the BBEG. I could think of no better place than here to get some help on him. It's a gestalt game and I was thinking that he'd be a warlock//cleric with some prestige class fun thrown in. The campaign is going to run from lvl 5-20 I think so he needs to be a complete build that can grow with the PC's. The idea behind his character is that he's an evil mage who builds suport for himself with the common people while slowly weakening the surrounding governments but basically fries anyone who gets in his way. If you've read L.E. Modesitt's Recluse series, think Antonin the White Wizard. Any help? Ideas? Thanks!

[CASTLEMIKE]

I like the +0 LA Soul Locked template from Heroes of Horror for a recurring villain the PCs may be able to kill a few times before he rejuvenates (Maybe he sold his soul to acquire the template).

I prefer SAD synergy with gestalt casters: Beguiler/Artificer (Int) with no ASF in light armor and lots of known spells for spontaneous casting and any other spell you want to give him, a Sorcerer/Warlock (Char) with the Leadership feat maybe with the Mage of the Arcane Order (1 - 7 levels with a Ring of Theurgy is really good for a sorcerer) or the Fiend Blooded and Hellfire Warlock PRCs, a Psychic Warrior/Cleric (Ur Priest) (Wis) or a Beguiler/Psion (Erudite with the Spells to Power variant for cherrry picking spells) (Int) or Push the gestalt boundaries as a DM with a Factotum/(Beguiler/Specialist Mage, Master Specialist, Ultimate Magus, Arch Mage or other PRC).