Armor Class 18 ({@item plate armor|phb})
Hit Points 52 (8d8 + 16)
Speed 30 ft.
Skills Arcana +4, Intimidation +2, Perception +3
Senses passive Perception 13
Languages Common plus any one language
Challenge 4
First Strike. The reckoner has advantage on initiative rolls.
Longsword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage, or 8 (1d10 + 3) slashing damage if used with two hands.
Lightning Backlash (Recharge 5–6). When a creature hits the reckoner with an attack, the attacker takes lightning damage equal to half the damage dealt by the attack.
Guildmaster's Guide to Ravnica, p. 231