So how's this sound for a maximum-magic-destruction setup?
1. Wear Crown of Dusk (+10% magic dmg)
2. Equip young dragon, bellowing dragoncrest, and magic clutch ring (a whopping 47% magic dmg boost for all 3!!) In the 4th slot i would probably equip ROSP, lloyd's sword ring, or chloranthy.
3. Hold Scholar's candlestick in your offhand for another 12.5% magic dmg if you are casting sorceries like CSS, but if you are gong for melee like me, just buff your weapon of choice with darkmoon blade (scholar's candlestick only affects your currently equipped catalyst's spellbuff, so you can't cast a buff like DMB and then switch to the candlestick for the damage boost).
4. Watch your enemies' life bars melt away as you obliterate them a total magic dmg boost of 57%, or 69.5% (!!!) if you use the candlestick.
I'll be trying this setup on my current character as soon as I have all the items (still need to farm concords for DMB). There aren't many enemies in this game that are weak to magic (I don't believe there is even a single boss who is weak to magic unfortunately), but i'm betting that the potential 70% boost will make magic more effective even against bosses like the dancer and abyss watchers, who are extremely weak to fire and lightning, respectively. To anyone who's already tried setups like this, I'd love to hear your thoughts.