This is a good idea, I have a similiar build. Spells are firestorm, poison cloud and acid cloud, plus 2nd chance. Left hand is tower shield +5, ToB. Right hand is baby's nails & scraping spear. The rinky-dink scraping spear does only about 30 (r1) or 80 (r2) damage, but that's not what kills thems. It's the plague and poison. As they keep their distance from the scraping spear, their health is slowly draining. When they go to eat any grass (except dark moon), I r2 attack. The plague and poison already decreases the grass effect, plus my attack takes away the little health they did gain.
The firestorm is in case they turn to run and I backstab them, the backstab doesn't do much damage but the firestorm does as they stand up. An I don't use the acid cloud either. If they happen to knock off my 2nd chance, I'll cast it just as a cover to recast 2nd chance, most people won't come running through it to try and interrupt the miracle, especially after being poked to death with a scraping spear.
The technique is don't just go running in attacking with the spear, you'll get backstabbed. Shield up, poke 1ce or 2ce as they attack, then roll back to regain stamina. Rinse and repeat.
But for your initial question, my "main" weapon (alternate, once all their gear is broken) is a makoto+5. 10 dam/sec bleed, plus it swings very fast. Good in case you run into someone with blind or LSoM, it swings faster with a greater reach.
