[1.2.321] Skill Balancing - Edelstein & Leben

Shadow Partner doubles the number of attacks. If you would have hit one Crit and one Noncrit without it, you will hit two Cits and two noncrits with it. It does not create additional chance for critical damage.

The damage with Savage Blow is: a + b + c + d + e + f, where each letter is a different number on screen.
With Shadow Partner, it's just: a + b + c + d + e + f + 0.4 * (a + b + c + d + e + f). Not: a + ... + f + g + h ... + l

All it does is clog the screen with damage shown and take up space in Etc from Summoning Rocks.