I have a build planned out (No, it's not optimized - I'll describe it in a minute) that enters first into Ur-Priest, then into Runecaster. I'm simply unsure as to what to use for the entry - a Cleric doesn't work well, because of UrPriest's flavor (I don't think I could convince a DM to let me worship one god, but steal divine power... Unless one of you has a rational argument?), which would make me lose EVERYTHING from cleric because ex-clerics are just... terrible... Druid wouldn't work well for me either (I'm not a fan of druids, personally) - though they may work for the build.
The build focuses around having Runecaster around to make some permanent runes for on-the-cheap fun things (I don't believe I'll be able to exploit it with the current DM), having the UrPriest for entry into Runecaster (3 levels in UrPriest, then 8 in Runecaster? 11 levels for full-on spellcasting? And with a measly level 16 as well? Perfect.) For damage/ encounters, I found out that (with two flaws), I can get all the prerequisites for Runecaster and UrPriest, then also Transdimensional Spell, Energy Substitution (Cold + Electricity), Energy Admixture (Cold + Electricity), Lord of the Uttercold, and Born of Three Thunders.
I'm open to suggestions for changing the metamagic - but I don't quite understand how Divine Metamagic works (Do you need the metamagic feat first? Or just Divine Metamagic, and then pick one you might not even know?), and I really like the idea of being able to make cold/negative energy/ sonic/ electricity spells (Not sure if I can combine both of them, though...) and also powerful runes.
Basically I'm looking for a base class to enter as, and then metamagic suggestions if you all have any (and being the CO boards, I'm sure you guys have plenty).
(Question: take any given spell, give it Energy Substitution (Cold) and energy Admixture (Electricity). Then give it Lord of the Uttercold, then Born of Three Thunders. Does that make it 1/4 Cold, 1/4 NE, 1/4 Sonic, 1/4 Electricity?)