Overt Operative

Assemble is a keyword action in the Unstable set that puts Contraptions onto the battlefield. Outside of silver-bordered cards, only one card (Steamflogger Boss) refers to assembling a Contraption. Cards and mechanics from the Unstable set aren’t included in these rules. See the Unstable FAQ for more information.

Menace is an evasion ability.

A creature with menace can’t be blocked except by two or more creatures. (See rule 509, “Declare Blockers Step.”)

Multiple instances of menace on the same creature are redundant.