Moments after the communication was sent, a coordinates and an invitation was delivered to them, and an escort came to help guide them there...named Voltron....
Some might think this was an intimidation tactic, if they knew about Voltron. But those would also know Voltron is known as the "Legendary Defender", not the "Legendary Weapon" or "Legendary Attacker". In other words, it was totally harmless so long as you did not start shooting innocent people.
If they followed, and landed at the docking area provided, they would be met by the King Himself, the Commander of the Royal Knights, the Rosetta Dragon Knights, and the young Prince Zakar, who was doing his best not to wonder why he was here.
"I would have thought Bastion would be the one you would bring".
"I wanted to bring all of you, but Bastion is busy on an experiment at the academy he said 'Cannot be interrupted due to great risks', and Amillia is sick with the flu. Besides, you are a wonderful, adorable grandson that is also a Prince of our nation!"
"...and your a king who is also a doting grandfather..."
"Shush" the king said, but then he just seemed to suddenly snap back into a kingly appearance. "Besides, you are the oldest. Once I am gone, you will be inheriting the throne".
Those words caused Zakar to be silent for a moment, remembering his deceased father who was killed by terrorists four years ago, and his mother who died giving birth to Amillia despite the technology and magic they had prepared. Truly, nothing was perfect in this world, even if you had both magic and technology. It was a ibtter lesson Zakar learned through one of the worst ways possible.
"Very well" he replied. He could not completely hide he wanted to be doing other things, but he was also interested in the newcomers as well, so he steeled his resolve. However.... "But, did you really need to send Voltron?"
"I thought it would be a good idea, to show one of our planet's guardians and heroes doing this".
"And, by that you mean you are acting like a kid showing off a new toy, even if its not new?"
"Oh shut up! They will be here soon!"