Boon of the Dragon Rider (5e Epic Boon)

You have won the favor of a powerful dragon, and gain the following benefits:

You learn the Find Greater Steed spell, and may cast it once per long rest without expending a spell slot. When you cast the find steed spell in this way, you may summon any Large or smaller dragon instead of the normal options available.
You can speak, read, and write draconic.
Dragons whose alignment is similar (though not necessarily identical) to your own will regard you as an ally, unless your actions prove otherwise.