Actions

Multiattack. The diviner makes three Arcane Burst attacks.
Arcane Burst. Melee or Ranged Spell Attack: +7 to hit, reach 5 ft. or range 120 ft., one target. Hit: 20 (3d10 + 4) radiant damage.
Overwhelming Revelation (Recharge 5–6). The diviner magically creates a burst of illumination in a 10-foot-radius sphere centered on a point within 120 feet of it. Each creature in that area must make a DC 15 Wisdom saving throw. On a failed save, a creature takes 45 (10d8) psychic damage and is stunned until the end of the diviner's next turn. On a successful save, the creature takes half as much damage and isn't stunned.

Reactions

Portent (3/Day). When the diviner or a creature it can see makes an attack roll, a saving throw, or an ability check, the diviner rolls a d20 and chooses whether to use that roll in place of the d20 rolled for the attack roll, saving throw, or ability check.