Resistance. Being a Fey as well and now a Fiend, she is resistant to fire and poison.

Legendary Resistance (3/Day). If she fails a saving throw, it can choose to succeed instead.

Be Afraid.  Targets hit with an attack could get a condition like stunned, frightened, poisoned, blinded, etc. Easy change is to impose the condition until end of the target's next turn, but it could go longer. Longer duration should offer saving throws to end the condition at the end of each of the targets turns, once they save they are immune to this effect for a 24 hrs.

Multiattack: The god makes three melee attacks: two with its rose thorn sword and one with its tail. It can use Hurl Flame in place of any melee attack.

Frightful Presence. Each creature of the new gods choice that is within 120 feet of her and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the Fledgeling God's Frightful Presence for the next 24 hours.

Tail: Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 15 (2d8 + 6) slashing damage.

Rose Thorn Sword. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 12 (3d6 + 2) slashing or piercing damage, and the target is cursed if it is a creature. The magical curse takes effect whenever the target takes a short or long rest, filling the target's thoughts with horrible images and dreams. The cursed target gains no benefit from finishing a short or long rest. The curse lasts until the god dies.

Censor (hanging incense burner): Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.

Acid vapor: The god lights the censor and spins it around themselves. Acid smoke fills the air in 10 feet wide radius around them. Each creature in that area must make a DC 22 Dexterity saving throw, taking 15 (2d6 + 8) acid damage on a failed save, or half as much damage on a successful one. Whoever breathes in the acid vapor will have disadvantage on their next roll. This action can only be used once.

Veil: The Fledgling God targets one humanoid or beast that she can see within 30 feet of her. If the target can see the god, it must succeed on a DC 14 Wisdom saving throw or be magically charmed. The charmed creature regards the god as their leader to be heeded and protected. Although the target isn't under the Aconite’s control, it takes the god’s requests or actions in the most favorable way it can.
Each time the god its allies do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until Aconite dies, is on a different plane of existence from the target, or ends the effect as a bonus action. If a target's saving throw is successful, the target is immune to the Fledgling God’s Veil for the next 24 hours. Up to three targets can be charmed at a time.

The Fledgeling God can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Aconite regains spent legendary actions at the start of its turn.

Detect. Makes a Wisdom (perception) check.

Reinforcements. Aconite calls for her followers. Any within a 120 foot radius hears her call. They are under her control and will fight with everything they have to protect or heal her.