Commander Jerome can call in Theseus after the Command Mantis ability has been researched from the Armory. Once researched, an active ability will be unlocked for the Commander Jerome hero unit, which calls in Theseus. The Command Mantis is a completely separate unit from Jerome, although he can enter and pilot it, in which case it will gain the use of two missile launchers. Much like Forge's Warthog, Theseus cannot be hijacked by enemy Spartans or be piloted by anyone but Jerome. However, Theseus' missiles cannot be used at close ranges, which puts Theseus at a disadvantage when facing Goliaths or melee-type hero units - in such cases, it is usually beneficial to have Jerome disembark.