The shows have yet to get this aspect right. Hayward was a 3/10 for me and Karli a 1.
Agreed. Karli was honestly the worst since Malekith. Agatha was by far the best from the shows so far (mostly thanks to Kathryn Hahn), but even she wasn't fleshed out enough IMO. We didn't get enough of a sense of what exactly she wanted to do with Wanda's power once she got it.
Here's hoping that Loki can improve in this department!