Dunno if you intend to adjust these tropes to Doskvol, nor the answer to your question, though, if you are looking for some inspiration, there are some interesting sources I can reccomend to you.
The Ovate is something of a mix between a monk and a druid. ( https://imgur.com/a/QPuPS )
The Shriek could very well fit the theme of a 5e warlock ( https://imgur.com/a/yeOwbuN )
The artist is like a "layers of fear" version of a bard ( https://drive.google.com/file/d/0B0w0-06KlXTeN09GcFd2TXpGNHc/view?usp=sharing )
There's also the iruvian playbooks :)