Dragon Rider

The Dragon Rider is a member of the Dragon Rider Corp that operates out of the Sarnastia continent in the realm of Zalanthia. They are young men and women who have taken up an oath to bond with a dragon and protect those against dragons and other creatures who wish to do harm to the world. As their bond grows stronger with their dragon, they become stronger themselves and are able to do more when the dragon is nearby. Dragon Riders can draw on their dragons core and use their dragons magic type. Dragon Riders must have strong bodies in order to use their dragons magic so STR should be your top ability.

Novice Rider

At 3rd level you can draw on your dragons core and channel their magic through your arm for an attack if you expend a Core Magic slot. The attack will deal 1d10 plus your STR  modifier of your dragons magic type.

You have two Core Magic slots per long rest.

Ascendant Rider

At 7th level, you have reached the rank of Ascendant Rider. Your body is stronger and can cast stronger magic. Channeling magic through your arm will now deal 2d10 plus your strength modifier if you expend a Core magic slot. You can also use a Core Magic slot to use the Dragons Breath spell as a 4th level spell.

You have 4 Core Magic slots per long rest.

Champion Rider

At 10th level you have reached the rank of Champion. You and your dragons bond is stronger than most in the corp. Channeling magic through your arm will now deal 3d10 plus your STR modifier. You now use the dragons breath spell as a 5th level spell. Expending two Core Magic slots grants you the ability to use "sense sharing" with your dragon which allows you to see and hear what the other does.

You have five Core Magic slots.

Dragon Lord

At 15th level, you have reached the rank of Dragon Lord. This is a rare title to have because most do not live to reach this rank but your strength is known by all. Channeling magic through your arm now deals 4d10 plus your STR Modifier if you use a Core Magic slot. Dragons Breath can be used as a 6th level spell if you expend a Core Magic slot. Expending three Core Magic slots allows you to push your dragons magic type through your legs into the ground dealing 5d8 plus STR modifier in a 15 ft radius to all creatures except you.

You have six Core Magic slots.  

Drake

At 18th level, you have reached the rank of Drake. You have ascended so far that you are starting to take on the features of a dragon such as hardened skin. Channeling magic through your arm deals 5d10 plus STR modifier if you use a Core Magic slot. Dragons Breath can be used as a 7th level spell if you use a Core Magic slot. Expending three Core Magic slots to push magic through your feet into the ground deals 7d8 plus STR modifier in a 15 ft radius to all creatures but you and your dragon. Since you have developed dragon like scales, your AC increases by +2.

You now have seven Core Magic slots per long rest.