Use Howl of Shabriri instead of Flame Grant Me Strength (I didn’t realize I was using it this run).

You can get a fully charged shot off at the beginning and not get hit by his first strike. Charge a little bit in front of him rather than point blank and you should have time to dodge his lightning strike attack. Wait to dodge his 2nd attack, then you should have a window to finish him. I messed up the timing this try, but you should be able to then dodge his 3rd attack for a no damage kill.

Setup:
No armor
Dancer's Charm
Red Feathered (seppuku health down to trigger)
Godfrey Icon
Scorpion Lightning Talisman
Golden Vow
Flame, Grant me Strength (use Howl of Shabriri instead )
Lightning Crystal Tear
Faith Crystal Tear
Ancient Dragons' Lightning Strike