Battle Roar. As a bonus action the alpha can utter a thundering cry to war. Any other brute within 30 feet gains advantage on all attacks until the end of the next turn. any hostile creature within 30 feet must make a wisdom saving throw (dc 17) or be paralyzed until the end of the alphas next turn. 

Servant of Kevmar.  As an action this creatures draws on the power of the abyss and unleashes a fist attack against one target.  +9 to hit, on a hit it deals 8d10 necrotic damage and heals the alpha based on the damage dealt. 1/day

Multiattack. The giant makes two greatsword attacks.

Greatsword. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 28 (6d6 + 8) slashing damage.

Bite. Melee attack +12 to hit, reach 5 feet. one target. Hit: (5d8 + 8) piercing damage. The target must make a DC 17 constitution saving throw and succeed or have its maximum hp reduced by the damage dealt until they complete a long rest or the greater restoration spell is used. 

Death Monger. As a reaction to being struck with an attack, the Alpha can move half its speed to attempt to get near the one that struck it. If it can reach the target it can make a bite attack against the creature with advantage. 

The vampire brute alpha can take 2 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. The alpha regains spent legendary actions at the start of its turn.

Greatsword. The alpha can make one greatsword attack.

Collectors Bounty. The Alpha marks a target it wants for a prize. This mark gives the Alpha advantage on all attacks against the marked target for 1 round of combat.