Vigour

Increases All Health Types.

The only tree that works in both forms, which is why it underpins almost every build. Techniques are gated behind manuals rather than pure level, so the tree advances at the speed you find books.

What it opens up

The manual that teaches it

The book itself, in 2 parts

The manual's own text, as the game writes it.

Rest of the Swordmastery tree