Arcane Advantage. Once per turn, the hobgoblin can deal an extra 7 (2d6) damage to a creature it hits with a damaging spell attack if that target is within 5 feet of an ally of the hobgoblin and that ally isn't incapacitated.
Army Arcana. When the hobgoblin casts a spell that causes damage or that forces other creatures to make a saving throw, it can choose itself and any number of allies to be immune to the damage caused by the spell and to succeed on the required saving throw.
Spellcasting. The hobgoblin is a 7th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 13, +5 to hit with spell attacks). It has the following wizard spells prepared:
Cantrips (at will): acid splash, fire bolt, ray of frost, shocking grasp
1st level (4 slots): fog cloud, magic missile, thunderwave
2nd level (3 slots): gust of wind, Melf's acid arrow, scorching ray
3rd level (3 slots): fireball, fly, lightning bolt
4th level (1 slot): ice storm
Quarterstaff. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit:4 (1d6 + 1) bludgeoning damage, or 5 (1d8 + 1) bludgeoning damage if used with two hands.
In hobgoblin society, the Academy of Devastation identifies hobgoblins with a talent for magic and puts them through a grueling training regimen that endows them with the ability to call down fireballs and other destructive magic on the host's behalf. A hobgoblin devastator on the battlefield is simultaneously a boon to all its allies and a threat to every foe around it.