The Engineering Rod is a Hardmode sentry-type summoning weapon that is dropped by Brain Scramblers, Ray Gunners and Gray Grunts. It summons a Tesla Turret minion to fire electric bolts at nearby enemies.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stats bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, Minions cannot deal critical hits. The only significant advantage a Mythical Engineering Rod has over a Ruthless one is knockback.