Dark Thrall Rune Knight

Undead Fortitude. If damage reduces the rune knight to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken. On a success, the rune knight drops to 1 hit point instead. If the damage that dropped it to zero is something other than bludgeoning, radiant or fire then the rune knight gets advantage on the save.

Turning Defiance. The rune knight and any dark thralls within 30 feet of it have advantage on saving throws against effects that turn undead.

Multiattack. The rune knight makes two melee attacks or two ranged attacks

Glaive. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 9 (1d10 + 4) slashing damage.

Leadership (Recharges after a Short or Long Rest). For 1 minute, the rune knight can utter a special command or warning whenever a nonhostile creature that it can see within 30 feet of it makes an attack roll or a saving throw. The creature can add a d4 to its roll provided it can hear and understand the rune knight. A creature can benefit from only one Leadership die at a time. This effect ends if the rune knight is incapacitated. 

Parry. The rune knight adds 2 to its AC against one melee attack that would hit it. To do so, the knight must see the attacker and be wielding a melee weapon.