Wiseman has (through means which he has not disclosed to Rubeus) arranged some sort of alliance with some sort of alternate timeline (the details of which he is also being cagy about. Wiseman is cagy about everything). Diamond has decided that the added danger of enemy interference from summoning their armies directly to 21st-century Tokyo is worth the cost it will save compared to bringing them there via Nemesis, so Rubeus has been tasked with deploying the black crystal device that is supposed to summon them.
Unfortunately, the Sailor Senshi have somehow managed to locate the operation and defeat his droid guards, and have knocked out of place parts of the device that Wiseman had stressed would need to be carefully positioned in order for it to work.
Three people will find themselves suddenly in the middle of a room filled with strange black crystals, where five girls with brightly-coloured hair, sailor suits, skirts, tiaras and elbow-length gloves and a man in a tuxedo and domino mask are facing down a man in a brown waistcoat and camouflage pants with a black crescent tattooed on his forhead.
All seven combatants look towards the new arrivals, whose appearance is, judging by their expressions, a pleasant surprise for the man in the waistcoat and an unpleasant one for the other seven.