Least Bosses DS1 (no RTSR)

Thief, Black Firebombs

5 bombs on asylum, darksign after gate before asylum dies
pick up bandit knife, talk to oscar, leave asylum

Kill Petrus, pick up bones, 400 soul, bone back

Pick up 200 soul, buy rapier + bow from merchant, get GPR

Go through havel, wrong warp to andre, take UP bonfire
Kill gargs with resined bandit knife, ring bell, bone back

Buy Longsword, 9 titanite shards, upgrade to +5 (saves 2 hits on Iron Golem, so its probably a little faster to not upgrade)
SGS, go through Sens
Resin and R2s for Iron Golem (8/9 for stagger, 4/5 for fall off)

Dupe IG soul twice on elevator, go through AL, take bonfire before OnS, level up 27 STR, rest END
Pick up DT, kill OnS, use IG soul on elevator, kill gwynevere, bone out

Warp to Firelink, get FAP ring, three smough soul dupes on elevator to New Londo
Fall Damage Cancel down, use smough soul on waterwheel, level up 30 END on blighttown bonfire
Trigger Quelaag, bone back, Quelaag skip, ring bell, bone back

Warp to firelink, kiln skip
Kill Gwyn