At some point, homo sapiens became a thing, as opposed to all the other homo etceteras. This has since been generally regarded as a bad move by the universe or gods or what have you and made many people rather displeased, human and otherwise. The Shra!kal Empire in particular was deeply offended by... something? It wasn't really clear. Regardless, they decided to put those upstart monkeys in their place. Humanity (well most of them anyway, some wanted to just nuke them and be done with it) collectively shrugged, prepared a medium patrol ship to travel to the Empire's capital just in case, and invited a Shrakal delegation for a weapons demonstration.
The Galactic Union and the TGC (also sometimes known as the Gaia Governance Group, or 3G, or sometimes the Terran Confederation) had more or less only just met each other after all, and the translators were... well, even decent would be something of a stretch, but you could more or less work out what the other party was saying, so the hope was that this little parade would let everyone go home and just disregard this whole thing, instead of having to like, spend a little bit of fuel. Really, paperwork was the main deterrent, but saving fuel sounded slightly nobler.
The delegation showed up at the agreed-upon meeting place, a basically uninhabited star system no one would miss if something happened, and in particular a rather desolate planet. The moon visible during the day was kind of pretty though. The traffic control VI of the gate station noted that the ship wasn't broadcasting authorization codes or a flight plan, estimated the maximum plausible threat of the ship, and prepped a single low-yield missile for launch. Then it ran diagnostics on its threat estimation routines, concluded they were working correctly, and prepped another 19 missiles, just in case.
The delegation landed on the planet only somewhat conceited. On one hand, they represented one of the most powerful factions in the Union, but on the other hand, they were technically in enemy territory. They walked over to the human commander standing outside a 700-meter-tall facility. It couldn't be called a skyscraper though, it was far wider and longer than it was tall.
"Greetings/hello/acknowledgment. Today/thisday/rightnow we're/wewill/weare demonstrating/showing one/singular weaponplatform/weapon/vehicle/tank." The human snapped their fingers and the structure behind them started moving. Rapidly. "This/that/theentity is the Hercules/mythlightninggodson mark/version/iteration 3."
Stolen from its original source, this story is not meant to be on Amazon; report any sightings.
The representatives were still recovering from the shock of seeing the thing move. "It/thetank has/contains/uses backup/secondary fusion/combining reactors/generators and tertiary/third fission/separation. It can/does mine/extract/process entire/whole mountains/geologicalfeatures. It can/does produce/create/manufacture swarms/hives/tides of robotic/mechanical troops/soldiers and furthermore/inaddition its/belongingtoit own ammunition/projectiles/explosives."
The translators were doing their best. Really, considering how difficult just translating between English and say, Mandarin is, let alone between languages of species from entirely different sections of space, it was quite impressive. Translation tech was one thing that the Union had put far more research into than the TGC.
One of the representatives spoke up. "What about its main weapon?" The human snapped their fingers again and pointed up. It took about 1.5 seconds for the arrangement of the photons hitting the representative's eyes to majorly change. Such change was because the moon was no longer reflecting light particularly well. Really, it wasn't doing much of anything very well, unless you count being a rapidly expanding ball of plasma.
"Variable/differing/customizable-yield/power/force antimatter/notmatter/oppositematter skipgate/warppush cannon/gun/launcher. Now/currently youplural may/might be asking/querrying/wondering why/whatreason I/singular am letting/allowing/permitting youplural to look/observe/review for possible/feasible/potential weaknesses/failings/defects/vulnerabilities in it/thetank."
The human laughed a little before continuing. "One/firstly/primary even if/despite/notwithstanding youplural do find/locate/observe weaknesses/failings/defects/vulnerabilities, youplural still have/must/requiredto deal/workaround with every/all/any human/homosapien in human/homosapien space/area/territory being able/capable/ready to manufacture/create/produce multiple/many/morethanone via/byusing fabricators/assemblers/constructors. Two/secondly, it/thetank is several/many versions/marks/iterations outdated/outofdate/obsolete. Imagine/conceptualize/visualize current/present weapons/weaponplatforms."
The next day the war declaration was itself declared by the Shrakal Empire to be a hoax, the perpetrators unknown.