First off: Mods - if it is too early to post questions regarding the RoE book, please let me know and remove this post. I am trying to minimize spoilers, but even so. I don't want to ruffle any feathers.
Onto the main question. Rage of Elements, Page 26 has the Tremor feat, which does 1d8 damage. But the scaling adds d10 damage. Are they supposed to be different dice, or are they supposed to be mixed die types? Just wanted to confirm.