Astarion would probably IMO be a swashbuckler or duelist rogue arc-type, with a very cut throat attitude. Now, I don't even know if there is such a thing for that in 5e or not.
To the best of my knowledge - there is not. They simplified everything, leaving no room for an interesting story, so players can focus more on simplistic stories.
Can we just replace Astarion with Inigo Montoya
Only if we get to make a reply: "I don't even know who the fuck your father is. Who is this man that I supposedly killed?!"