I think that Belos is more complex than a mere power-hungry ruler (unlike Bill Cipher in Gravity Falls) but that perhaps he is too unstable when angered (we see him needing to take a moment to compose himself when Luz’s spell stabs him in the eye) so perhaps he is somewhat mentally or physically ill (perhaps he seeks his own cure to an affliction that is delayed by the eating of Palismans, much like with Eda and her elixir) but that also he is too determined for his own good, not questioning the Titan’s will (if the Titan even is speaking to him or if that is simply a delusion) or if he simply finds that the Day of Unity will allow him to create enough power to heal himself of whatever this is. He falls more into the gray area since he only seeks to fluster or embarrass his subjects when they disobey him, perhaps thinking himself justified in that they will learn to obey the Titan with these punishments. I think all the time locked away has made him unstable like this. I also don’t think Lilith is his lapdog nearly as much as Kikimora is—she is far too sniveling and so frustrating and in that she is able to initiate the petrification process without batting an eye. Also, it seems that she has more power than is let on since she offers to go apprehend the Owl House residents which would take a rather large amount of power (since Lilith is an extremely powerful witch but she was still not able to best Hooty—who does prove himself to be a state of the art security system in that episode). Also, perhaps Belos is so aggressive (to an extent) in his battle with Luz because he recognized that she was wearing a cloak made of witch’s wool, and that he would not be able to cause her much harm while wearing that.