Dael Braam (dwarf) is a cooped up farmhand looking to see the world, but being immune-compromised from birth it took a lot of persuasion to convince her parents to let them go. They relent under the condition that she finds a capable and strong person to travel with to keep her safe… Just so happens that a strong and capable centaur knight is visiting in town…

Rembrandt (horsey) was created from a dark fusion spell by an amateur mage, who had intentions to construct a powerful warrior to do his bidding.

However, the spell cast did not result in a powerful and fully-armored warrior…. but instead a frail baby knight centaur, with only its top half made of living armor. The mage, not wanting to raise any kind of child, promptly abandons his creation. He can always try to make another one after all.

Into adulthood, Rembrandt still carries a lot of pent-up abandonment and self-esteem issues. You wouldn't know that from the proud facade he puts on though, lying about being a royal knight yet helping all those he comes across with a smile, but never staying long. When the opportunity of having a long-term travel companion (and perhaps a friend…?) arises from Dael requiring a bodyguard, his craving for companionship and affirmation outweighs his worries about her seeing eldritch elements of himself.

Dirk (beefy dragon thing) is the second (and more "successful") attempt from the same mage to create a powerful monster. Think Rembrandt's "big evil" brother. Except he's quite a bit younger. Dirk emerged fully-developed except for his wings-which remain as little nubs. Despite his brawn and warrior-appearance, Dirk was mostly a glorified errand boy, using his impressive strength to terrorize the nearby towns and their land-collecting resources for the mage.

Dael and Rembrandt meet Dirk after hearing word of a giant dragon-knight ravaging villages (and their livestock yum yum).

(I also like the idea of the mage sending Dirk to capture Rembrandt + Dael when he recognizes is his first attempt is not only alive and strong, but also quite proficient in battle.)

One way or another Dirk ends up roaming with the two. At first, Dirk is over-confident, rude, and stubborn... Overall a huge pain for them to travel with. After being shown kindness for the first time and being subject to more than a few humbling situations, Dirk allows a protective, loyal and softer side of him to emerge.