OK, finally got my STR 16, so I can wield the Drake Sword one-handed.
Holy shit, this thing is amazing. It one-hits all the current Undead I'm facing in Undead Burg and Parrish. Unfortunately, it doesn't thrust, only swings, and it seems to only deal damage to a single target.
I've been using a Longsword, which not only hits multiple targets, it does that even on a thrust/lunge. A couple of times, I've engaged multiple targets, which has been fine with the Longsword, but not with the Drake Sword. When it hits, though.

Also accidentally killed the boar. I dropped some fireballs on it from the bridge there, and didn't account for movement. Fell off the bridge, and the boar gored me once. While I was trying to pound Estus Flasks, I rolled behind a flaming corpse. The boar followed me into it, and then just stayed there until it was char-siu.
This Fanged Boar Helmet is ridiculous looking.