Fun drink mixers/add ins that can be used as shave ice flavor, as well?

My family does a thing where we each get gifts that suit the whole family/things we all enjoy. I’m out of board game options and my parents love to make drinks and try alcohol while my younger siblings love our new shaved ice machine.

Is there anything or some syrup that is popular both as a drink mix in and a flavor for ice deserts? Thank you!