Liam Neeson's character berates a mass murderer for "always following orders" while Ralph Fiennes is also present. Mass murder using the excuse of "following orders" was a major theme of Schindler's List also starring Neeson & Fiennes.
Hephaestus (Bill Nighy) says "Release the Kraken!" in reference to events from previous Titans films, but also to his appearance in Pirates where his character released the Kraken for his own purposes.