Mine own character will probably need a bit of rules support. Huorn, King of Talloughborough, rides himself a dusk unicorn named Telemnair. But between you and me, getting access to a legendary creature is just overkill: let’s just take a nightmare and juke it.
Say I go fighter 2/bard 13. That’s still enough for 7th level spells, and as a lore bard, I get magical secrets — the 6th level conjure fey or, since I’m aiming for Challenge 3 for nightmare equivalency, maybe just an obsidian steed. Er, maybe pearlescent steed. Whatever.
|Charmed, Paralyzed, Poisoned|
|, passive Perception|
|If the fairy steed moves at least 20 feet straight towards a target and then hits it with a horn attack on the same turn, the target takes an extra 9 (2d8) piercing damage. If the target is a creature, it must succeed at a DC 14 Strength saving throw or be knocked prone.|
|The fairy steed has advantage on saving throws against spells and other magical effects.|
|The fairy steed makes two attacks: one with its hooves and one with its horn.|
|Melee Weapon Attack: to hit, reach 5 ft., one target. Hit: 7 () bludgeoning damage.|
|Melee Weapon Attack: to hit, reach 5 ft., one target. Hit: 8 () bludgeoning damage.|
|The fey steed touches another creature with its horn. The target magically regains 11 (2d8+2) hit points. In addition, the touch removes all diseases and neutralizes all poisons afflicting the target.|
|The fey steed teleports itself, its rider, and any equipment it is wearing or carrying up to 60 feet to an unoccupied space it can see.|