Secondary Magics

Secondary, tertiary, etc. magics are magics learned by a mage other than their main magic.

Secondary
Sages of many types of magic can learn another type of magic closely related to their main. The ability to learn a secondary magic is generally a marker of reaching the sage level. It is more difficult to train a secondary magic than a sage's main magic, but hypothetically it is possible to train a secondary magic to be as powerful as a sage's main magic.

Tertiary
Some types of magic have an additional magic that can be learned beyond secondary magics, generally marking attainment of the archsage level. These magics are less closely related to the mage's main magic, or may be advanced specific skills(e.g. blood magic for water archsages). Tertiary magics are even slower to train than secondary magics, but again, an archsage could train their tertiary magic to be as strong as their main magic.