Hey there, a while back I read a Monster Hunter, Mass Effect crossover. This is lore based a bit on that story.

50 CE

During the Rachni Wars, an Asari scout ship crash lands on an unrecorded world while escaping an attack by the Rachni. The world is full of monsters and massive beasts. Even with their weapons and biotics, these Asari would not have lasted against these creatures if they had not made contact with the natives: the Monster hunters. A total of three new sentient races were discovered, the Asari-like rough and plentiful humans, the small, furry, and naturally linguistic Felynes, and the tall long lived Wyverians. This was the first time first contact was made with a race (or three in this case) which had yet to even develop space travel. The hunters were very helpful towards the Asari, both fascinated with each other for multiple reasons. The stranded Asari quickly adapted to this world thanks to their help, however the biggest surprise was yet to come. A group of Rachni had also crash landed on the planet and set up a small hive. However as the soon as they were discovered, it ended up with the Rachni participating in a massacre that forever changed the galaxy. The hunters were very strong, with physical abilities and strength long since lost by more advanced races due to reliance on guns and other modern weaponry. Not only did the weapons size help, their heavy armor made from the monsters roaming the planet turned out to be stronger and more durable than some of the greatest kinetic barriers, the only effects the guns having being the force of impact pushing them back a bit. Speaking of the monsters, after the hunters managed to kill the Rachni queen that set up shop on their planet, several different monsters of all kinds flocked to the nest and slaughtered the remaining Rachni with ease. The stranded Asari now realized they had the key to ending this war.

55 CE

Five years after getting stranded, the Asari finally recieve aid and return to Citadel space. Upon arrival, they explain everything in great detail. All that they had learned about these new races, how they survived all the monsters that existed, and most importantly how easily the Rachni were beaten. Even showing videos of hunters cutting through normally overwhelming amounts of Rachni with ease. All of this knowledge is overwhelming. Three primitive races on a planet full of monsters can easily take down a foe they had not been able to gain an advantage over for decades. There is much debate, but in the end, it is decided the Hunters would be uplifted instead of the Krogan.

60 CE

In five years, the hunters have integrated into galactic society and have started their campaign against the Rachni. The hunters even when presented with modern guns and armor, they outright refuse. Prefering to keep to their low tech ways in ground combat at least. Many military leaders doubted they would last long, only to be shocked in every way possible. Sometimes low tech is the way to go.

300 CE

The Rachni War finally comes to an end. During a raid on the last known Rachni hive, the hunters steal a queen egg before obliterating the hive. When asked why they did this, the hunters said they did not want to condemn the Rachni race to extinction, and would instead raise this surving egg to be better than her predecessors. Many thought it was foolish and pointless, only to be proven wrong when the hatched queen agreed to limit her kinds expansion and retreat into seclusion with minimal contact. The hunters have done what many races thought impossible, made peace with the Rachni. See, the hunters have had a growing reputation over the years. The humans have become known as honourable and respectable warriors, with strength thanks to not being so advanced. The Felynes ability to speak without the need of a translator draws admiration, as well as their cute appearance, great cooks, impressive durability and determination, and unique speech habits. The Wyverians being able to live as long as an Asari as well as how they involve themselves in the affairs of short lived species causes them to be considered even wiser than the all female race, much to the annoyance of several matriarchs. With overwhelming popularity and having just ended a war, the Citadel Council accepts the Hunter Council as one of the head races. The councl seat is split between the three races, each having one third the power of a full councilor.

325 CE

Over 25 years after the end of the Rachni Wars, a new technology independent of Mass Effect technology is discovered: Bioenergy. Bioenergy is the energy of life itself, with all lifeforms in the galaxy possessing trace amounts of it. For some reason, it is especially strong on the hunter's homeworld. Many scientists theorize it is why the life on the planet is so abnormally strong. After experimenting with it, it is discovered Bioenergy can be used to cure several previously incurable diseases and can also be used to actually terraform barren worlds, a feat previously thought completely and totally impossible. Tests begin on how to utilize this.

336 CE

Study on the Ancient Civilization of the hunter homeworld is done in hopes of possibly helping with the still developing terraforming technology. It is discovered that the Ancient Civilization actually predated even the Protheans by hundreds of thousands of years, and were even more advanced but never bothered to expand into to space. Further study results in more questions than answers. The monsters of their world were nothing compared to them, and many of the races which currently inhabit the world were a part of the Ancient Civilization. And the fact that the Fatalis was able to destroy it and revert the people back to the stone age draws major fear. As for why they never expanded, it is theorized they just never had any interest. It is brought up the possibility of studying and using the Ancient Civilization's Equal Dragon Weapon in the hunters care, but the hunters quickly explain the forbidden act and how the price was too high to pay to create it. The amount of life needed to make a large enough army of Equal Dragon Weapon was equal to draining ten to 20 garden worlds of all life. It's only thanks to the high Bioenergy concentration of the hunters homeworld that allowed the Ancient Civilization to create the Equal Dragon Weapon. Further study is difficult, like people of all different times, even during the Ancient Civilization's time, were trying to erase their technology. The only people who at least try to advance upon the little technology left are the hunters. Weapons sich as the switchaxe, gunlance, chargeblade, demolisher, and dragonator being prime examples. The Ancient Civilization is too different from the Protheans for the rest of the galaxy.

359 CE

The first ever Bioenergy terraforming bomb of mass creation, or Bio-nuke is developed. Once launched at a barren world, it releases a massive amount of potent Bioenergy from the hunters homeworld, causing life to develop in as little as 45 years or accelerating the development process of what little life already existed. The terraforming can be a bit slow after the first 45 years, but introducing monsters into the planet's environment seems to accelerate the process. Due to monster introduction, a majority of these terraformed planets are given to the hunters. This is mainly due to the fact that the hunters need to remain in a Bioenergy rich environment for at least a quarter of their life. If they don't, it has been discovered their bodies become incredibly weak, in some cases they end up dying very quickly.

432 CE

The truth about the mysterious and infamous elder dragon Xeno'Jiiva is discovered. It turns out Xeno'Jiiva is the result of a Thresher Maw becoming heavily mutated by large amounts of Bioenergy. This is first discovered when a Bio-nuke accidentally crashes into a Thresher Maw nest, causing it to become a Xeno'Jiiva. Xeno'Jiiva's infamy skyrockets, partially due to the fact it is capable of using direct energy attacks, something that has yet to be properly developed using technology. While the rest of the galaxy panics, the Hunter Council steps up to handle it. It is decided that the Hunter Guild will no be exclusive to the hunters worlds. Instead, they shall be open to the entire galaxy. Anyone who is having problems with monsters can post a quest at the nearest hunter hall or can actually train aliens to be hunters, starting at a young age. Once again, the popularity of the hunters skyrockets.

500 CE

Even though the plans for uplifting the Krogan were said to be abandoned, there were Salarians that did it anyway. This was done in hopes of countering the hunters quickly growing power, making the Krogan into anti-hunter weapons. They didn't agree with the Salarians, turning against them. The Krogan rebellions have started, Krogan aggressively expanding like the Rachni. The Council is furious with the Salarians for this, with hunters having to step in to handle this.

700 CE

The Krogan and hunters have been in a stalemate for over 200 years. The hunters strength and abilities keeps the Krogan from having that advantage, but even to this day the hunters have never really been good with warships. The Rachni were caught by surprise with the hunters, but the Krogan had information they took from the Salarians about all the different races. The council makes first contact with the Turians and persuades them to join the war.

710 CE

The Genophage is launched against the Krogan, slowly ending the war. While the rest the galaxy is glad the war is over, to everyone's surprise the Hunter Council is furious. Hunters possess a great respect for life and natural evolution, so something like the Genophage was a complete insult to their beliefs. They knew how bad the Krogan's breeding problem was, but did not believe this was the way. Add to this, the Salarians used Bioenergy meant for a Bio-nuke to create the Genophage. The Hunter Council does not respond kindly to this. The hunters cut off all trade of Bioenergy with the Salarians and also threaten to leave the Council unless promised that Bioenergy will never again be used for something like the Genophage, and develop a cure which will modify the Genophage completely. They also threaten to shut down the hunters guild to the rest of the galaxy. The Council has no choice but to accept their terms. The hunters have become too vital in their society to loose. Bioenergy from terraformed planets is not potent enough for making Bio-nukes, only Bioenergy from the hunters homeworld can be used and even then not much can be extracted without completely obliterating the environment. Plus the hunter guild has saved many colonists from large Thresher Maw attacks, becoming major public heroes.

900 CE

Despite the hunters protests, the Turians are still granted a seat on the Council. Development on a cure for the Genophage is slow going, but the hunters suspect that is purposeful, but cannot do a thing since they cannot gather proof. Meanwhile, the hunters have been integrating several Krogan into their society, trying to make up for the actions of the Turians.

1895 CE

The Geth War happens. While the majority of the galaxy ban the Quarians from settling on other worlds, the hunters do not. When asked why, the hunters stated they actually expected this to happen. They said it is the nature of all life, even artificial life, to evolve and adapt. It was only a matter of time until the Geth became self aware and rebelled. They tried to warn the Quarians of this, but they didn't listen. Now they will make it up to them. The Quarians' integration into hunter society causes a major boost in terms of naval power for the hunters.

2157 CE

Contact with the humans of Earth is made.

Well that's it, hope you enjoyed it.