Elden Ring: Shadow of the Erdtree - Sekiro Deflections vs Messmer The Impaler (Solo) 

Spam blocking works most of the time in my experience

Spam blocking doesn’t work as well, as there’s a tiny delay between pressing the block button and your character actually blocking. So you can get hit during the start of the blocking animation

It works fine.

He did

m'lady sword with deflection tear