Undead Fortitude. If damage reduces Maviela to 0 hit points, she must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, she drops to 1 hit point instead.

Undying Fury. Maviela has advantage on Strength checks and Strength saving throws. She has advantage on Dexterity saving throws against effects that she can see.

Reckless Attack. When Maviela makes her first attack on her turn, she can choose to roll with advantage on melee weapon attack rolls using Strength during this turn, but attack rolls against her have advantage until her next turn.

Partial Elessar. While Maviela has the Partial Elessar on a cord around her neck and she takes radiant or necrotic damage, she reduces the damage taken by 5. 

Vitriolic Vitality. 1/day. Maviela can cast Dragon's Breath at a second level (save DC 15) choosing acid as the damage type. 

Multiattack. Maviela makes two weapon attacks when she takes the attack action:

• Treetrunk. Two-Handed Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:  1d12+6 bludgeoning damage.

Blighted Storm Aura. As a bonus action, Maviela can send a wave of acid extending 10ft. from her. All creatures in the aura take 3 acid damage.