Hawk Knight wrote:
May I also suggest that Dark Kin Horn Attack at the end of a move be a bonus action. This will put it in line with similar abilities in 5e. Otherwise it's stepping on toes of the Charger feat and makes it too powerful. Also how does it interact with monk abilities? Can Dark Kin monks make their unarmed attacks with them? If so then that damage needs to scale properly. D6 at first level is too much, but at 11th lvl too little.
As others have pointed out, only a very small handful of feats are allowed in the SRD. All the other ones are available as choices in the Living Arcanis campaign, but we can't print them or make reference to them in our Arcanis 5e products.
Horns are meant to be a replacement for the regular unarmed strike everyone has. A regular unarmed strike deals 1 + STR bludgeoning damage and everyone is proficient with their unarmed strikes. The horns deal 1d8 + STR piercing damage instead; they are a replacement effect. Anything that interacts with unarmed strikes, like the monk's Martial Arts feature works with the horns.
Let's look at Martial Arts. It says:
Martial ArtsAt 1st level, your practice of martial arts gives you mastery of combat styles that use unarmed strikes and monk weapons, which are shortswords and any simple melee weapons that don’t have the two- handed or heavy property.
You gain the following benefits while you are unarmed or wielding only monk weapons and you aren’t wearing armor or wielding a shield:
You can use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes and monk weapons.
Since the horns are unarmed strikes, you can use Dex instead of Str for damage and attack.You can roll a d4 in place of the normal damage of your unarmed strike or monk weapon. This die changes as you gain monk levels, as shown in the Martial Arts column of Table: The Monk.
Since the horns are unarmed strikes, they have a 1d8 damage die right out the gate. You can choose to use the die from the table, but it doesn't become better than a d8 until 17th level.When you use the Attack action with an unarmed strike or a monk weapon on your turn, you can make one unarmed strike as a bonus action. For example, if you take the Attack action and attack with a quarterstaff, you can also make an unarmed strike as a bonus action, assuming you haven’t already taken a bonus action this turn.
As long as you are taking the Attack action with an unarmed strike or a monk weapon you can make an unarmed strike with your horns as a bonus action.Certain monasteries use specialized forms of the monk weapons. For example, you might use a club that is two lengths of wood connected by a short chain (called a nunchaku) or a sickle with a shorter, straighter blade (called a kama). Whatever name you use for a monk weapon, you can use the game statistics provided for the weapon.