Crystall Guardian

Mindless Servatude. The crystal guardian can hear nothing but it's masters voice

Crystal Skewer. The Crystal Gradian strikes the ground and rises a crystal spike in four unoccupied spots on the map within 100 feet of it. These Spikes are impossible to pass through or over, as they rise into the ceiling. They reflect all projectiles at a mirror angle to how they were originally fired.

Laser strike. Laser beam +5 to hit, range 300/900 ft., multiple targets. Hit: 34 (8d6 + 10) Lightning damage. This attack can pierce up to 6 targets. 

Crystal Punch +7 to hit, range 5 ft., multiple targets. Hit: 24 (4d6 + 12) bludgeoning, if this hit is successful, a 26 (4d10 + 6) piecing spike impales through the target and out 10 feet behind them. If anything is hit by this, it also takes damage. This spike is magical.

Echo Screech. Everything but the crystal guardian makes a dc 10 charisma save. On a failure, the creature becomes frightened.

Crystal Punch +7 to hit, range 5 ft., multiple targets. Hit: 24 (4d6 + 12) bludgeoning, if this hit is successful, a 26 (4d10 + 6) piecing spike impales through the target and out 10 feet behind them. If anything is hit by this, it also takes damage. This spike is magical.

The crystal guardian has 5 legendary actions every turn.

Collapse Collam (Costs 1 Actions). The Crystal Guardian Chooses a crystal skewer and makes it explode. This sends several crystal shards out from the pillar in all direction around the pillar. these shards have a +3 to hit, do 15 (4d6 + 3) damage.