Infusions. The raider has two items infused with magical properties: its chain shirt which provides a +1 bonus to its armor class (included), and its spellcasting focus which provides a +1 bonus to its spell attack rolls (included). If the raider dies, these magical properties end 3 days later.

Spellcasting. The raider is a 3rd-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 14, +7 to hit with spell attacks). The raider has following Artificer spells prepared:
Cantrips (at will): fire bolt, shocking grasp (see "Actions" below)
1st level (# slots): expeditious retreat, faerie fire, false life, feather fall, shield, thunderwave

Multiattack. The artillerist uses its Eldritch Cannon and casts a spell with a casting time of one action.

Eldritch Cannon. The raider magically creates an eldritch cannon and fires concussive blasts. Ranged Spell Attack:  +7 to hit, range 60ft., one target. Hit: 9 (2d8) force damage.

Fire Bolt (Cantrip). Ranged Spell Attack: +7 to hit, range 120 ft., one target. Hit: 5 (1d10) fire damage.

Shocking Grasp (Cantrip). Melee Spell Attack: +7 to hit, reach 5 ft., one creature. Hit: 4 (1d8) lightning damage and the target can't take reactions until the start of its next turn. This attack has advantage if the target is wearing armor made of metal.