I did a spell sword build, I call I the "Fire Bug" because it was focused more on pyromancy than sorcery. A fire infused long sword will see you through most troubles, I used a crystal sword too; but it was never stronger than the fire sword with a focus on Intelligence. Just as powerful actually, except in the Smoldering Lake where the crystal sword was a godsend. Then I switched to Faith and used a lightning infused longsword because lightning is more broadly useful, especially against dragons. With an infused weapon in one hand, and a spell catalyst in the other; it's a very engaging build where you have options to dodge, attack, or use a spell as you see fit. Equipping Sage Ring, clutch rings, and rings that increase pyro/sorcery/miracles damage output as a trade off to defense is risky; but you'll feel like badass.