Clockwork Conductor

Construct Nature. Doesn't require air food drink or sleep.

Immutable Form. Immune: form-altering spells/effects.

Magic Resistance. Advantage: spell/magic effect saves.

Metronomic Aura. When a friendly creature within 20' of conductor makes an attack or Cha (Performance) check creature can treat d20 roll as a 10 instead of die's actual roll.

Conductive Baton. Melee Weapon Attack: +3 to hit, 5 ft., one target, 3 (1d4+1) bludgeoning damage + 4 (1d8) lightning and target can't take reactions until start of its next turn.

Overclocked Finale (Recharge: Short/Long Rest). Makes a grand sacrifice spurring its allies on in a final masterstroke. Each friendly creature within 30' of conductor that can see it gains a +5 bonus to attack rolls damage rolls and ability checks until the end of the conductor's next turn. Roll a d6. On a 1 to 4 conductor can't use Concerted Effort until it finishes a short rest. On a 5 or 6 it can't use Concerted Effort and its Metronomic Aura becomes inactive until it finishes a short rest.

Concerted Effort. Inspires itself or one friendly creature it can see within 30' of it until start of conductor's next turn. When target makes an attack roll or a Con save to maintain concentration on a spell target can roll d4 and add result to attack or save.