Isn't magic very similar to Eragon (and rooted deeply in the Earthsea)?
There are nice twists containing promises (also in Eragon); However what took 1k pages in Eragon here was much more condensed (in a good way!);
The difference is that "Life Energy" from Eragon could be taken by force, while here it needs to be given willingly (which kills idea of self-sustaining death spells that were natural extension of Eragon magic)
#SFFBookClub