Notes:

Apparently some fans have noticed similarities between Sardonyx and Bayonetta. Here's some stuff taken from the SU WIki:

"Fans have noted there are many similarities between Sardonyx, and the PlatinumGames character Bayonetta. Both pose dramatically in front of the moon before performing an attack, both are classy and self confident, graceful yet incredibly strong, and both have a fondness for children (Bayonetta with Cereza & Loki, Sardonyx with Steven). They both taunt before finishing off their targets, and both have the same snarky means of addressing bystanders during battle.
-Coincidentally the way Sardonyx uses her war hammer is identical to how Bayonetta uses her Hammer weapon, the Takemikazuchi, from Bayonetta 2.
-Sardonyx's theme is also similar to the upbeat Bayonetta series soundtrack."