Anthemic Tandem Warpriest

Anthem of Dissolution: Throughout combat, the Warpriest will attempt to concentrate on the Lyrics of the Anthem, whilst casting Chorus of the Anthem every turn after starting to concentrate. 

Anthem of Dissolution can be synced with a song with both a normal and instrumental version, and with the lyrics coming in when Lyrics of the Anthem is active, and Chorus of the Anthem occurring when the song's chorus occurs!

Lyrics of the Anthem: When active, all targets within 50ft experience a -2 modifier to all saving throws. After concentrating for 1 Turn, the Warpriest can cast Chorus of the Anthem. Interrupting this spell cause a burst of light, healing all affected targets by 1d4 and removing 2 stacks of Exhaustion, whilst also inflicting Discordant Rhythm on the Warpriest. Requires Concentration.

Discordant Rhythm: If Lyrics of the Anthem is interrupted, the Warpriest receives -2 to all Saving Throws for 2 Turns, and cannot resume the Lyrics of the Anthem for 1 Turn.

Instrument-less: If the Warpriest is disarmed in any way, then it loses access to all spells, and can no longer cast Lyrics of the Anthem.

Spellcasting. The Anthemic Tandem Warpriest is a 4th-level spellcaster. Its spellcasting ability is CHA (spell save DC 13, +4 to hit with spell attacks). The Anthemic Tandem Warpriest has following custom spells prepared, with descriptions attached: 

Arc-Chord Wave (Cantrip): The Warpriest unleashes a 20ft cone of pure Tandem energy in front of them; targets must make a DC Dexterity Save, else they will be struck with 5 (1d6+4) Lightning damage and left Blinded until their next turn.

Thunderous Crescendo (1st Level): Every 4 Turns, and whilst Lyrics of the Anthem is active, the Warpriest can end it early, lifting his axe into the air and focus the Anthem into a singular target; the target must succeed a DC Dexterity OR Charisma Save, else they take 22 (4d6+5) Radiant damage. On a successful save, the damage is halved.
+5 Radiant damage per Spell Slot Lvl above 1st.

Gather the Choir: Every 5 Turns, the Warpriest can summon 1d4 Tandem Altos. 

Tandem Axe Slam: The Warpriest slams their axe into the ground around them, sending out a shockwave: +4 to hit, reach 10 ft, all targets within range. Hit: 12 (2d6 + 2) Bludgeoning damage. 

Chorus of the Anthem: Once every 2 turns, the Warpriest unleashes their Voice; all targets within 50ft must roll a DC Constitution Save or take 18 (2d12+4) Radiant damage and gain +1 Level of Exhaustion. Can only be cast when Lyrics of the Anthem has been active for more than 1 Turn. Successful Saves still take half damage.