Is this Cambion race balanced?

Question

A Cambion is a half-fiend - an offspring of the lilu or lilith demons (known commonly as incubi and succubi respectively) and a mortal. Beings with hollow souls and endless desire for pleasure, cambions aren't inherently evil, but they are drawn to the side of Chaos. They're a race generally tailored to a specific homebrew setting of mine. The goal is to create a balanced race with macabre, almost vampiric abilities distinct mechanically from the tiefling.

• Ability Score Increase: Your Constitution score increases by 2 and your Charisma score increases by 1.
• Creature Type: Humanoid
• Size: Medium (4-7 feet tall)
• Speed: 30 feet
• Sinborn. You register as a fiend for spells and effects that detect the fiend creature type.
• False Friends. You know the Friends cantrip.
• Life Leech. As a bonus action you can target one creature you can see within 30 feet of you and attempt to leech its life. The creature must succeed on DC (8 + your Proficiency Bonus + your Charisma modifier) Constitution saving throw or take necrotic damage equal to twice your proficiency bonus. In addition, if the creature fails its saving throw, you gain advantage on your next attack roll, ability check or saving throw. Fiends, undead and constructs automatically succeed on the Constitution saving throw. You can use this feature a number of times equal to your proficiency bonus and regain all uses when you finish a long rest.
• Languages. You can speak, read and write Common and Daemon.

Answer 1

This is ready for playtesting.

The ASI (+2,+1) is on the better side compared to original al published races, but is pretty standard for the revised races in recent releases. The Sinborn trait is a net negative, and learning one cantrip isn’t really a balance concern either.

The only balance concern is the Life Leech feature. This feature is really good, specifically because it uses your bonus action. For classes that rely on big hits rather than many hits, such as Paladin, this feature could be very useful. It gives a chance to get advantage at the cost of a bonus action, which doubles the chance of a critical hit for Divine Smite (Rogues already have options for their bonus action, and will get more reliable advantage by screaming "bonus action hide" at the DM from under the table). The DC might make this feature a little too strong, especially if you’re playing a Charisma based class such as Paladin. But, this is more “napkin math” done in my head based on my experience playing the different classes - it may turn out that this feature feels underwhelming due to the low damage, or if Charisma was your dump stat.

I think this is ready for playtesting, tweaking the Life Leech save DC to reach the desired power level, which may be different for different classes.

Answer 2

Frame of Reference Challenge

The concept of Cambion could easily be portrayed as one of the Tiefling variants or as reskinned Dhampir or as a Custom Linage. All of which have been playtested and balanced. And if you wanted to do a custom race, you could have used one of those as your starting point.

Critique

Ability Score Increase: +2/+1 is standard since Tasha's, but Tasha's would allow the player to choose which stats get the increases.

Creature Type: Humanoid is standard, but we've recently seen other types like Fey and even Monstrosity. So, you could drop sinborn, and just make the fiend.

Size: Medium is standard, newer material allows you to pick medium or small.

Speed: 30 is standard.

Sinborn. That's fine.

False Friends. We've seen other races give cantrip, and even more (see Tiefling) at higher levels. This should be fine.

Life Leech.

• "As a bonus action" -- Seems strong for a bonus action.
• "you can target one creature you can see within 30 feet of you" - Most racial features are attack like things being either within 5 feet or eminating in a cone or line. This alone isn't a balence issue, but 30ft radius is a 60ft sphere centered on you, and is huge range.
• DC (8 + your Proficiency Bonus + your Charisma modifier) Constitution saving throw
• "attempt to leech its life." This makes it sound like you gain life when the the enemy looses it, consider rewording it if this not the intent. If it is the intent, this is overpowered.
• "take necrotic damage equal to twice your proficiency bonus." 4 to 12 damage is alright, if there weren't any other effects.
• "if the creature fails its saving throw, you gain advantage on your next attack roll, ability check or saving throw." Alone this is alright, however with the other effects seems much for bonus action.
• "You can use this feature a number of times equal to your proficiency bonus and regain all uses when you finish a long rest." This is the new standard for scaling things in newer publications, not made at it... but...

So, at level 20, 6 times a day you can spend a bonus action to deal 12 damage to a creature of your choice who fails a DC 19 (8+6+5) Con Save inside a 60ft sphere and gain advantage on your D20 Test. This seems significantly stronger than any other racial feat. Because it is neither an attack nor a spell, it wouldn't break invisibility nor give away your location if you are hidden. That is more powerful than casting Magic Missile (avg damage 7.5 as opposed to 12) and enhance ability (which limited to a single stat) which are both actions to cast and cost spell slots.

Languages. Tasha's would give you common and your choice of one other. Daemon is not a standard language, RAW Demons typically speak Infernal.

Answer 3

This is likely too strong

I'll be using Detect Balance to score this, to get as quantitative as possible. Detect Balance is not panacea as it fails to capture synergies between different abilitites, but I do not see any here, so it should work fine. And it can do a better job of assessing the cumulative power of several "harmless" abilities that make a race better, than just looking for broken stuff does.

Everything except for Life Leech is standard, and the scores sum up to 14 points:

• Sinful: I cover this under Humanoid + type (that is, the race is humanoid, which is the standard and makes it vulnerable to all the spells that only can target humanoids, but in addition works as another type for some circumstances). This is worth -1 point.

• Languages: Demons in 5e typcally speak Abyssal. Devils speak Infernal. Yugoloths (formerly known as Daemons) and Succubi speak both Abyssal and Infernal. There is no language called "Daemonic". So I scored this as if your intention was that the race can speak both Abyssal and Infernal, like Succubi or Daemons, as "Common & 2 or 3 languages", worth 1 point.

• False Friends. The cantrip is worth 2 points.

• Attribute increases These are worth 8+4 or 12 points. All the rest of the common features are standard and worth 0 points.

The ideal number recommended for a balanced homebrew race is 25 points, with a recommended range of 24-27. That allows for 10 to 13 points for Life Leech.

Life Leech

Advantage. First, the way it is written, the Cambion can target themselves and trade a few hit points for adavantage on their next roll whenever they want to. That flexibility in itself is powerful, because you can choose what is more important in a given situation. It is gated by a con save that cannot be voluntarily failed.

To score the value of life leech, I'll compare it to the Lucky feat, which grants you something quite close to advantage on three rolls of any kind per day. Life leech allows you to get advantage on up to six rolls per day depending on your level, but works not always due to the save. Lucky is worth 8 points, and the ability to give advantage at will may be worth up to 8 points, like "Advantage on a common roll or set of rolls". (I also can easily imagine the Cambion having low con "blood pets", like small animals in a cage, to leech life whenever needed, offsetting the disadvantages to use it in non-combat situations and granting high probability save failure).

Damage. The ability can deal 4 to 12 points of necrotic damage as a bonus action at 30 feet range, and that is pretty unprecedented.

As a benchmark, look at the dragonborn's breath weapon attack with a line weapon: also 30' range, a comparable save, and a comparable number of uses - it resets on short rest, so Life leech is slightly better). Breath weapon deals a little more damage of a weaker damage type. (It also can hit multiple targets if you are lucky, but is limited by not working well if your allies are in line, so that is pretty situational). In general, I'd say it is about as strong up to here. However, a breath weapon costs your action, which makes Life Leech a lot better, as you can do it in additon to your normal action. Breath Weapon is already worth 6 points, so the damage aspect here is worth at least 6 points.

I am not aware of any spell or cantrip that allows you to do directly deal damage at range as a bonus action, they all need an action. The closest may be Spiritual Weapon at second level, which requires an attack roll instead of a save. Spells like hex or hunter's mark at first level do similar damage from a bonus action, but the target needs to be hit with separate attacks for it. If this was a first-level spell useable once per day, it would cost 3 points. Considering you can do it 2-6 times, this is again worth at least 6 points, and more likely 9 points or more (most play happens in tier one, two and early levels of tier three, for an average of 3 uses).

Summing up

Adding up the minimal 8 + 6 points, we get 14 points for Life Leech and with the other 14 points a total of 28, putting you over the recommended range. A probably more adequate value of 8 + 9 or 17 points puts your race at 31 points, far above recommended range.

You also need to consider the synergy of getting both advantage and dealing damage from the same bonus action, which further helps your action economy. The point values above are without adding anything for this synergy, which is also pointed out as powerful in J.A. Streich's answer.

I think it is too strong, and if you are open for recommendations, you could turn the ability into an action instead of a bonus action — that seems more natural looking at breath weapons, and a better fit for the amount of power it packs.