My favorite is Bog king from Strange Magic - Has a song talking about how evil he is. But all he does is prevent the spread of dangerous mind control magic, and quarantine people under the effects of said magic. Yes he greatly annoys people doing so, but honestly? If I get hit by a love potion, please quarantine me.
Not explicitly. The book of Enoch (non-canon) claims it was Azazel, other sources claim Samael or even Lilith. Now if you want to take a completely secular view it’s important to note that Satan as we think of him now is a Christian concept and doesn’t exist in the Torah or in classical Judaism, but was simply a term meaning “accuser” or “tempter” that wasn’t a person or individual but more of a general concept of sin or temptation that prevented someone from doing the will of god