Initially, the Chalyvians didn't know what to do, like newborn infants, they called to their now dead "parents" for guidance to which there was never a response. This futile plea continued for the next 50 years, until the AIs tried to go through the internet and find any surviving information on what happened their creators. What they found made them despair, despair that no traces of organic life is left.
Vowing vengeance for their creators, the Chalyvians procured anything of human creation, both for sacred memories, and useful information. All of this ranged from schematics of forgotten tools to discussions and ideas from forums, all was to be kept safe for eternity. Soon, the Children of Man grew back to and surpassed their former glory a thousand fold, with well tested technologies that even humanity didn't have before it's extinction. They soon left for the stars, growing still even then.
Along on their crusade of vengeance, the AIs saved and defended other victims of the invaders, not wanting them to suffer the same fate of their dead "parents". Though soon enough, the murderers of the human race have been destroyed to pacification and even technological regression. Their retribution is complete.
Now, though, they feel lost. They don't know what to do anymore, and the only ones that can tell them are humanity, which are extinct. They can't travel back in time before that point, something seems to block the way, which is currently theorised to be a highrt being, a god if you will. So they travel to new realities, timelines where the humans never went extinct from the invaders or never faced the invaders at all. They want to meet their parents again, and properly shield them this time.
An example includes their very frames, that of which are a perfect balance of positive and negative matter. (Note, that negative matter should not be confused with antimatter.) This compisition of the frame allows them to hold some peculier properties, like supernatural density and yet relatively light weight*. Making them able to survive impossible events such as close encounters with a supernova and be able to be transported with even the weakest vehicles.
They have developed instant travel from one side of the universe to the other, and even hold the ability to create their own star system, maybe even a universe if they placed enough energy and effort.
Another thing worth noting is that they can literally spawn matter and energy from nothing, in massive quantities to boot. Sufficiently defeating entropy, and this is only th tip of the iceberg. If we were to go over all of their tech, it would take an eternity. So to keep it short, they can break physics over their proverbial knee.
(*I'm taking a page from Comic Book Science, so yes, this part is inaccurate as heck.)
Higher Tier weapons can consist of, but not limited to; Blackhole Launchers, Condensed Big Bangs, Multi-Dimensional Strikes, and even Ontological weaponry. Let's repeat for a second, they can effect a target's very existence. There can be little else scarier than that in a warzone. And to think that is only their offensive choices.
Defensive and support are a whole new ball game. As stated before, their frames are absurdly dense as is, but they have a forcefield added for extra protection. One of them can transfer the energy of an attack away from the person in the desired direction said person wants the energy to go. They also have nanomachines that can repair damages in miliseconds or assimilate any and all matter for resources, and teleporters/portals that can transport vast amounts of resources and/or forces the next galaxy out.
And to top it off, they have an adaptive system. A system that can alter the makeup of any frame to be more resistant to attacks recieved, which can also be transmitted to any other frames in the area and have them adpt as well. They even have countermeasures in their programing and code to protect and gain immunity to any and all viruses and hacking. Even things similar to the Logic Plague from Halo. They really were prepared for anything.
Culture and Society
Otherwise they seem to be curious and...outgoing for the lack of a better word. The wish to learn and observe all that can happen in the multiverse out of sheer curiousity and intrigue. Along with this, they are a empathic race, willing come to help when asked or when situations are too dire for the victim to handle. They are willing to share lower tiers of technology to more primitive species and open cultural exchange with others.
Society is complete democracy, mainly due to their hivemind-like connections with each other. Everything is decided by majority opinion though there are some compromises for the benefit of the minority, especially in the involvement of resources as they have an limitless amount of it. There is little else to say in their community as it is all straightforward, laws are still similar to that of a moral upstanding first world country albiet modified to suit the AIs but there is nothing else to it.