@khashir: 50int is too high, you only want that on an enchanted weapon build, dragon breath is not worth it, it even sucks @45dex. 44int is the highest one would normally go, if only for crystal spear and logans scaling. something for you to consider is 32int with 45dex, i'm a big fan of that:
http://mmdks.com/3vmt this concept lets you cram in all the mg dmg boost gear and ends up FAR more damaging than 50int with logans or crystallization alone..all while staying (albeit frail) a true melee char at the core. a more conservative (fair/duelist/roleplay) form: http://mmdks.com/3dgq and the "i'll make your life hell"-loadout: http://mmdks.com/3vmx (disclaimer: i only do lvl100, just add 20 levels of your liking on top and be good) the 45dex concept also lets you lol at the sight of GMB. to answer your remaining questions: black flame is frowned upon because it's really strong and dark orb is only usable @45dex imo but it becomes really strong (especially when mixed with other dark magic)
@culpahble: your ideas are a bit conflicting, velkas stat req. (16dex 40int) don't merit a strong buffable weapon. you could use a weak +15 rapier or claws or shotel as a buff vehicle and switch afterwards. if you want a strong buffed weapon, the weapon will still be strong after the buff runs out, no need for a backup then right?