From publisher blurb:
Within temples near the frozen tips of high mountains, a dragon in humanoid form trains its newest Dragon Knight in the stances and fighting styles befitting the Order of the Ryuuken. This new Dragon Knight subclass, heavily inspired by samurai and kendo, relies on martial prowess in the form of stance fighting, utilizing five different stances and several advanced fighting styles to choose from, and a secret technique once these are mastered.
In addition to this subclass, you can find within this document several new options, including Draconic Pacts, feats for spreading Draconic Pacts and other Dragon Knight features to other characters, and magic items with rules for synergizing their magic with the power held by dragons and those who make pacts with them.
Within this supplement, you can find the following:
One Draconic Order: the Order of the Ryuuken.
Three Draconic Pacts: Abyssal, Storm, and Undead.
Fighting styles and feats to expand upon Dragon Knights and other characters.
Eight dragon-inspired magic items, including an artifact for the Order of the Ryuuken and new rules for synergy with creatures who make a Draconic Pact.