Is this homebrew Dragon Rider class balanced compared to the other official classes in 5e?
Note that all the spells I've put on the Rider spell list require concentration.
The class:
Dragon Rider
Dragons terrify most adventurers, but for you, one very small dragon decided to bond with you, giving you the gift of magic as well. Why did the dragon choose you? Did your country or city test every citizen for a bond? Did you find your dragon still in an egg while exploring a abandoned dragon cave far greater adventurers cleared years before? Did you stumble upon it in the woods one day while hunting? Are the dragon's parents or a military looking for it?
Quick Build:
Intelligence should be your highest score as a Rider, followed by Constitution or Strength/Dexterity. Get starting equipment (c) and choose the spells Faerie Fire, Hunter's Mark, Arcane Weapon, and Thunderous Smite.
Dragon Rider Spell List
1st-level
Arcane Weapon
Ensnaring Strike
Entangle
Expeditious Retreat
Faerie Fire
Fog Cloud
Hail of Thorns
Hunter's Mark
Searing Smite
Thunderous Smite
Wrathful Smite
Zephyr Strike2nd-level
Alter Self
Blur
Branding Smite
Earthbind
Magic Weapon
Silence
Skywrite
Warding Wind3rd-level
Blinding Smite
Call Lightning
Crusader's Mantle
Elemental Weapon
Flame Arrows
Lightning Arrow
Protection from Energy
Vampiric Touch4th-level
Elemental Bane
Grasping Vine
Greater Invisibility
Staggering Smite
Storm Sphere5th-level
Animate Objects
Antilife Shell
Circle of Power
Control Winds
Far Step
Immolation
TelekinesisClass Features
Hit Points
Hit Dice: 1d8 per Dragon Rider level
Hit Points at 1st level: 8 + your Constitution modifier
Hit Points at Higher Levels: 1d8 (or 5) + your Constitution modifier for each Dragon Rider level after 1stProficiencies
Armor: Light Armor and Shields
Weapons: Simple and Martial Weapons
Saving Throws: Intelligence and Constitution
Skills: Choose 3 skills from Perception, Arcana, Nature, Medicine, History, Animal Handling, and Acrobatics
Tools: Leatherworker's Tools, Dragonchess SetEquipment
You start with the following equipment, in addition to the equipment granted by your background:
(a) a greatsword; (b) a longsword, 6 javelins, and a shield; or (c) a rapier, a longbow, a quiver with 20 arrows, and a shield
leather armor, an explorer's pack, and a leatherworker's kit.
Dragon Bond
When you take you first level in this class, you gain a pseudodragon companion with a permanent telepathic bond to you. You always know the location of your dragon as long as it is in the same plane as you. You and this dragon can read and speak Draconic, and you can communicate with each other at a distance of a number of miles equal to your level. As an action, you can see through your dragon's eyes.
If your dragon is killed, you suffer one level of exhaustion from the stress of having your telepathic bond severed. You can spend a long rest to bring it back to life. If you do this, you end your long rest with 0 mana points.
Spellcasting
Unlike other spellcasters, your magic comes from the power your dragon bestowed on you when you met it; thus, you have no spell slots. Instead, you have a maximum amount of mana equal to your Rider level. You regain all expended mana on a long rest. Whenever you cast a spell, you can spend 1 additional mana to cast it as if you were in your dragon's location.
Intelligence is your spellcasting modifier for Rider spells. You know 4 Rider spells from the Rider spell list and learn 1 more whenever you gain a level in this class.
When you cast a Rider spell, you spend mana according to the table below. If you do not have enough mana, you cannot cast the spell.
\begin{array}{cl} \textbf{Spell Level} & \textbf{Mana Cost} \\ \text{1st} & \text{1 Mana}\\ \text{2nd} & \text{3 Mana}\\ \text{3rd} & \text{5 Mana}\\ \text{4th} & \text{7 Mana}\\ \text{5th} & \text{9 Mana} \end{array}
Fighting Style
At level 2, choose between the Two-Weapon Fighting, Archery, Defense, Great Weapon Fighting, Dueling, or Mariner fighting styles. You can't benefit from the same fighting style more than once.
Mastery
At level 3, choose between the Spell Master and Weapon Master subclasses.
Ability Score Improvement
When you reach 4th level, and again at 8th, 12th, 16th, and 19th level, you can increase one ability score of your choice by 2, or you can increase two ability scores of your choice by 1. As normal, you can’t increase an ability score above 20 using this feature.
Using the optional feats rule, you can forgo taking this feature to take a feat of your choice instead.
Draconic Growth
At level 5, your pseudodragon grows up into a wyrmling of any color of your choice except red. No one (including you) can ride your wyrmling. Your wyrmling can only use its breath weapon once per short rest, unless it has multiple breath weapons, in which case it can only use each option once per long rest.
Improved Bond
At level 6, once per short rest, whenever you take damage, you can use your reaction to have your dragon take the damage instead. Additionally, once per short rest, your dragon can use its reaction whenever it takes damage for you to take the damage instead. Transferred damage cannot be reduced in any way.
Additionally, you automatically succeed on any saving throw against your dragon's breath weapon.
Draconic Tendencies
At level 9, your bond with your dragon begins to influence you. You gain proficiency in the Survival and Nature skills, your eyes continuously glow the color of your dragon, and you learn the Thaumaturgy cantrip.
Draconic Growth
At level 10, your dragon grows into a young dragon of the same color as it was as a wyrmling. One Medium creature or two Small creatures can ride on your dragon at a time. It still has the same breath weapon limitations as before.
Extra Attack
Beginning at 11th level, you can attack twice, instead of once, whenever you take the Attack action on your turn.
Riding Master
At level 13, you have advantage on saving throws you make to stay on your dragon while it is in flight.
Greater Bond
At level 15, when a creature takes damage from your dragon's breath weapon, that creature has disadvantage on saving throws it makes against your Rider spells until the end of your next turn.
Increased Draconic Tendencies
At level 17, you stop aging and can't be aged magically. You are immune to disease.
Draconic Growth
At level 20, your dragon grows into an adult dragon of its color. 3 Medium or 6 Small creatures can now ride it at a time, and it is no longer is limited in uses of its breath weapon.
Subclasses
Weapon Master
At level 3, when your dragon makes a critical hit on a creature, you have advantage on attacks against that creature until the end of your next turn.
At level 7, when you use your action to cast a spell, you can make one weapon attack as a bonus action.
At level 18, your ranged attacks are made at advantage while you are riding your dragon. In addition, if you move towards a creature at least 60 feet in a round, your first attack against that creature before the end of your next turn does an extra 4d10 piercing damage if it hits.
Spell Master
At level 3, you regain mana points equal to your proficiency bonus whenever you complete a short rest.
At level 7, you can use a bonus action to spend mana points and give yourself or your dragon hit points equal to the 5 times the mana points you spend.
At level 18, you learn one 6th-level spell and one 7th-level spell from the sorcerer spell list, and can cast each of these once per long rest.