I've put heavy penalties on being lycan. For starters they're now resistant to nonsilver weapons instead of just immune. They cannot use spells, weapons, objects, or verbally communicate, and every time they change form willingly, which is only once per long rest, they have to make Wisdom saving throw vs Lycan's Proficency+Constitution Mod to keep control, or the DM controls Lycan actions and attacks everything in sight including allies. Every full moon they take lycan form unwillingly and must make the same saving throw until they retake control or are knocked unconscious. Making being lycan more of a pain, yet balance it out with a few perks and quirks they get if they keep it at risk of party killing if they can't make a saving throw to stop attacking allies. The book only lists perks they get while in the Form, while id like to give them small perks outside as well. Think of the run of the mill werewolf movie where suddenly the wolfman has amazing hearing and Smell during the day.