With the backstab skill, just get onto the Admin tool, create a godly piercing weapon (ie: 300dmg 10dly), hit Commit Changes, note the item number, go back onto the server, summon it and there ya go
Or you could go into the source and mess with the damage code, I have no clue how to do that.....yet :P. Mana regen rate you can also mess in the source code if you know how, or just make items with clarity2 with effect or something along them lines.
You can control practically whatever you want with the Admin tool: Trade Skills, Items, Mobs, etc...