EvanNave55
Explorer
Definitely silence, first spell I thought of for taking down casters (followed by counter spell/dispel magic) I'm surprised only one other person mentioned it. A bunch of the other spells posters mentioned can be good too. For cantrips detect magic and one of the scag melee-magic cantrips are a must (assuming your going toe-to-toe with the caster, if you have melee party members with you you can leave it to them. I also thought something that could bind their hands would be good, but I don't think there are any spells along those lines so shatter as mentioned by [MENTION=6800621]Relic Dice[/MENTION] would be good (and quite creative,vi hadn't thought of that). Otherwise mostly just the general good go-to spells you would pick.
Oh, and sorry for any mistakes. I typed this with my phone.
Oh, and sorry for any mistakes. I typed this with my phone.