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 could, 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

Arcane Advantage. Once per turn, the hobgoblin can deal an extra 7 ( 2d6 ) damage to a creature it hits with a damaging spell if that creature is within 5 feet of an ally of the hobgoblin that 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 saving throw.