I have been looking back at some of my previous PCs and actually the concepts behind them all are rather tame. The stand out character in recent years is probably my illusionist.
Silas by game profession was an illusionist but was employed most of the time at the Nomikos Library as a freelance researcher. When not helping people find what they were looking for in the library he lead an Indiana Jones style double life as a hunter of dark wizards, warlocks and witches and anyone who used magic for evil purposes.
I was quite surprised how effective he was taking out evil magic users. Illusionist make great spies as their have amazing powers of disguise. The essence open and closed lists give good functionality for spying. He tended to take out the spell caster using Gate Mastery to summon creatures to fight for him whilst remaining invisible and out of harms way, in the dead of night, with surprise and when his target was sleeping.
For a profession that lacks a lot of fire power at lower levels he really punched above his weight.
This character is one that snuck up on the GM in that he became incredibly powerful. Right from the off I made a point of collecting Rune Paper. Most of the magic items I collected in my adventures were inherently evil and I took these back to the Nomikos Library and gave them to the library staff to dispose of. Obviously I kept any spell bonus items but I also collected Runes and Rune Paper. I think the GM started to compensate me for all these great but evil items I kept giving away.
I made a point of telling the GM when I created a new rune and as my ability to store higher level spells increased I would revise the spells I had stored as runes. As anyone who knows Spell Law will know that there are some truly brilliant low level spells. I ended up with nearly 60 sheets of rune paper and these represented something like 300 powerpoints worth of my most powerful low level spells bound into a ‘working spell book’.
So Silas the Witch Hunting Illusionist is my rather tame ‘Wildest Character Concept’
I am guessing you can all do better.