Character Analysis
The Duke's legitimate son, Lussurioso gets a lot of screen time in this play, and he's definitely on the villainous side. He's always sneaking around scheming, and he'll seduce any woman he can, with little concern for what his actions might do to her reputation. About the best thing you can say for him is that he doesn't seem to be a rapist (which, in fairness, makes him nicer than some of his family). He is, however, pretty freaking lustful:
Attend me: I am past my depth in lust,
And I must swim or drown. All my desires
Are levelled at a virgin not far from court,
To whom I have conveyed by messenger
Many waxed lines, full of my neatest spirit,
And jewels that were able to ravish her
Without the help of man; all which and more
She, foolish-chaste, sent back, the messengers,
Receiving frowns for answers. (1.3.98-106)
In addition to be lustful, Lussurioso's also kind of a jerk: He calls Castiza "foolish-chaste" here for rejecting his advances, despite the fact that they live in a society in which her chasteness is pretty important.
In addition to being a lustful jerk, though, we also see in the above passage that Lussurioso is pretty free with money (or, in Castiza's case, jewels). That said, money for this guy is all about bribing people to do what he wants, not, say, giving it to the homeless. He's also willing to kill for power, as we find out in the last act. Doesn't sound like the dukedom is going to be a lot better off when he takes over… so it's probably for the best that he gets killed before his I'm-the-Duke party is even over.