Europa Theme Park or Nice (French Riviera)

[Carvanafan]

I am thinking about tacking on a couple of days to our August 2026 Disneyland Paris trip for either Europa or Nice. I have never been to Europa (or Germany at all). The Youtubers are enticing me because it seems very disneyesque in that it is full of fantastic dark rides, which is my main thing. I visited Nice when I was in law school many years ago. It was cold and I was poor, so I made it a bucket list item to go back one day in the summer and stay at one of the hotels on the beach. This would be that opportunity. Trying to decide which one to do if I do either at all. Interested in people's thoughts on those experiences themselves but also the logistics. Not sure which would be easier or cheaper both in terms of travel between there and Disneyland and also US. Like if I do one of those options am I still better of flying in and out of Paris, or better to do multicity. Thanks so much for any insight!