Shadow Rider

Shadow Riders appear to most to be simple mounted rangers, but the true source of their ability is a bit more unusual.  Shadow riders learn to bond with spirit mounts that they can call upon when they need.  Many are even said to absorb some supernatural powers from their steeds making them impressive hunters and trackers.

Animal Training

At 3rd level, you gain proficiency with animal handling

Spirit Steed

At 3rd level, you learn the find steed spell.  The first time you cast this spell, you choose the permanent form of your steed and you must expend a spell slot and spend the full 10 minutes to cast it.  You may then cast the spell as an action a number of times per long rest equal to your Wisdom modifier without expending a spell slot unless your steed drops to 0 HP.  If you have no more free uses of this feature of if your steed drops to 0 HP, you must once again expend a spell slot and the full 10 minutes to return your steed to existence.

Your steed increases in strength along with you and gains HP equal to your Wisdom modifier each time you gain a level in this class.

Spectral Bond

At 7th level, your steed's bond with you gives you supernatural abilities.  As a bonus action, while you are mounted on your steed, you can cause yourself and your steed to become invisible for up to 1 minute or until you cast a spell or make an attack.  In addition, while you are mounted on your steed, if you drop to 0 HP, you can instead return to 1 HP and become invisible until the end of your next turn or until you cast a spell or make an attack.

Once you use either of these features, you cannot use the same one again until you finish a short or long rest.

Dark Fusion

Starting at 11th level, you and your steed may briefly meld into one being of shadow.  As a bonus action, you may transform yourself and your steed into a Centaur for up to 1 hour or until you end this effect as a free action.  Your size becomes Large and you maintain your mental statistics while in this form.  In addition, you gain resistance to nonmagical bludgeoning, piercing, and slashing damage and your movement does not provoke opportunity attacks while in this form.  When this form is reduced to 0 HP you and your steed separate into two creatures again with you taking any leftover damage.

Once you use this feature, you may not do so again until you finish a long rest.

Reliable Summoning

Beginning at 15th level, you may always cast find steed as an action.