The Invader (capitalized) is a battle type in the Metal Shadow universe. It describes an elemancer who focuses on infiltration of enemy ranks and reconnaissance. They can run circles around most units, and when armed with a mobile weapon, they can carve their names in the process. They can perform a variety of roles, from thievery to the assassination of weak foes.
The Invader is fast, but its attacks are not strong enough to stun bulkier opponents. A unit with strength to match the Invader's speed is therefore the natural counter to it.