Problem with the last battle
Ok here's my problem in a few words.
At level 20 the party will have a sorcerer with subtle spell and an archdruid which, if you don't know, will have the ultimate "I win" button:
Archdruid
At 20th level, you can use your Wild Shape an unlimited number of times.
Additionally, you can ignore the verbal and somatic components of your druid spells, as well as any material components that lack a cost and aren't consumed by a spell. You gain this benefit in both your normal shape and your beast shape from Wild Shape.
So, besides having infinite wildshapes (which is already incredible and not absolutely super OP), Vecna won't be able to use counterspell on him either. What do I do? Do you think it will be too easy for them? What do you recommend?