New Creature CR Help

[Prince Vine]

I'm creating a group of warlocks for my game and need help guesstimating CRs. I'm going to start with the first one I finished and get some insight since I hear the book is iffy at best with it. I used a 9th level character as the baseline and did some pruning and adding to get it roughly where it needs to be.

Winddancer
AC 16
HP 50 (9d8+9)
Spd. 30 ft

Str 14, Con 13, Dex 18, Int 11, Wis 13, Cha 14
Senses: Darkvision 60 ft.

Abilities:

Step Eternal: This creature can move as if it were under the effect of a Spider Climb spell. It can use a bonus action to take the disengage or dash action.

Unnerving Angles: This creature has advantage on attack rolls against creatures standing at a different angle than it.

Master of Gravity: This creature can fast Feather Fall on itself at will.

Actions

Multiattack. This creature makes two magical rapier attacks.

Magical Rapier. Melee Weapon Attack: +7 to hit, reach 5ft., one target. Hit 11 piercing damage (1d8 + 5)

Eldritch Blast. Ranged Spell Attack: +6 to hit, range 120 ft., two targets. Hit 6 force damage (1d10)

Gravity Flip (Recharge 5-6). Melee Spell Attack: +6 to hit, reach 5ft., one target. Hit The target treats a direction of this creature's choice as down for as long as this creature maintains concentration, up to one minute.

[Ninja_Prawn]

So, a couple of thoughts...

since I hear the book is iffy at best with it.

Really, the thing that's 'iffy' is using CR as a measure of relative monster power. The calculation in the book is the only valid way of arriving at a CR; the problem is that CR itself isn't a particularly accurate tool.

1d8+5 is not equal to 11. And generally with monsters, we round down.

The wording on gravity flip is a little ambiguous, but I'm going to assume you know what you mean. It doesn't affect CR, so I'll just ignore it.

Therefore, assuming the rapier actually does 9 damage at +7 to hit (4 from dex, +2 proficiency because there's no way this will have a CR above 4, +1 enhancement bonus assumed from the damage calculation), and allowing an effective +4 for the always-on advantage, this Winddancer would have a CR between 3 and 4 (so I'd rate it at 4 to be safe).

[Prince Vine]

Oh fun. I was afraid the potential 20d6 fall damage could be bad. Need to come up with a consistent fall stopping save.

[JNAProductions]

Unnerving Angles is very poorly worded. As written, the monster can lean slightly and gain advantage on every attack.

I'd probably nix it entirely.

[Ninja_Prawn]

If you're meaning gravity flip to be used as a weapon, it definitely needs to be more tightly worded. I had assumed it was supposed to be a non-damaging utility ability. Note as well that the attack bonus isn't going to be +8 when you correct the monster's proficiency bonus (and it's very unusual to run a magical ability like that off of Dex, but we'll roll with it for now).

So. If we nix Unnerving Angles, assume Gravity Flip is doing 20d6 every third turn, and drop the attack bonus to +6 (+7 for the rapier, but that's no longer the primary damage source)... the CR becomes... 3. Yeah, turns out Unnerving Angles is hugely impactful at this level. And big offensive numbers don't do you much good when your defense is made out of tissue paper.

[Prince Vine]

Unnerving Angles is very poorly worded. As written, the monster can lean slightly and gain advantage on every attack.

I'd probably nix it entirely.

It's only there for the forum. My game hands out advantage and disadvantage for dramatic swashbucklery actions (for 7th Sea flair), so advantage for attacking from the ceiling or walls vs more 2D creatures is a thing.

[Prince Vine]

If you're meaning gravity flip to be used as a weapon, it definitely needs to be more tightly worded. I had assumed it was supposed to be a non-damaging utility ability. Note as well that the attack bonus isn't going to be +8 when you correct the monster's proficiency bonus (and it's very unusual to run an ability like that off of Dex).

So. If we nix Unnerving Angles, assume Gravity Flip is doing 20d6 every third turn, and drop the attack bonus to +6 (+7 for the rapier, but that's no longer the primary damage source)... the CR becomes... 3. Yeah, turns out Unnerving Angles is hugely impactful at this level.

It's both. It's a 4th level version of reverse gravity (with more angles) that can be used offensively or as a high speed fly option. In the prepublish rewrite I will revert it to the fall in any direction wording.

I wasn't planning on them fighting these guys, but better to be prepare. You know what they say about plans and PCs...

[Crisis21]

You know what they say about plans and PCs...

The PCs only perceive the parts of a plan that allow them to screw it up.