This new major faction has unique play style concentrated around repairing fleets of their own or its allies, restoring planetary improvements destroyed by invasions, restoring destroyed planets.

Healers once was a tool of Eternals, like Cravers but used to repair things not to destroy them. After Eternals disappeared this tool evolved on its own is the far corner of the galaxy.

Here are the traits of this faction:

1. Galaxy is full of destroyed planets, remnants left from the old wars present in some of the star systems. Healers get huge buffs in science, motivation and dust, when repairing these planets, and also only they can found leftovers of planetary improvements on usual planets and restore them more quickly then building them from scratch.

2. Healers can repair their fleets and fleets of their allies with special support utility modules installed on their ships, unique to this faction. Healers ships have a lot of utility modules.

3.  They have unique combat tactics witch allow them to rescue almost dead ships from the battle, unless enemy has tractor beam, called rescuing path. After battle end their other fleet will repair these ships.

4. When fighting on planets they will restore some portion of their troops after each battle.

5. Healers CANT built obliterator and they don’t have planet destroying weapon, since it violates their nature.

6. Healers are support faction which gives and get many benefits to its allies, like repairing their systems, alliance with Healers will enable other factions ability to repair their planetary system improvements after it was destroyed by invasion, make their fleets to repair faster. Healers can also send fleet equipped with special modules to help their allies repair their systems.

7. Healers have huge debuffs when playing alone and is a bit week faction on its own.

great idea!

I think the name needs some improvement. Names which refer to a factions motivations or which have a unique sound to it. A new word or an unusual combination of words is good. Generally, you want to describe what shapes the faction. The cravers have a restless desire for consumption, but they aren't just called "the attackers". 

Restoring destroyed planets already works for every faction with behemoths. Theme wise, your idea sounds similar to the sowers from ES1 and as a minor faction in ES2. Actually, alot. They were also a tool of the endless.

Game mechanic wise, i think finding and using remnant structures of an old empire would have been an awesome thing for the nakalim. Well, we have glowy spaceballs to collect instead. That idea is good, although it has to be balanced fairly, i think. Rather than finding standard system improvements, i think they should find unique system improvements to add a sense of novelty. And as a sort of downside, other players who invade a healers world can use those improvements since the healers restored them. Similar how to others can use a cravers depleted world (well, that's not a benefit), or a world with a temple to the lost on it from the nakalim.

Be aware that "lots of utility modules" usually means that the ship carrying them is weak. The best ships have lots of weapons and armor instead, just enough utility modules for engines and a weapon enhancer. For defense oriented ships, auto repair systems can be helpful, aswell. But stacking those isn't that useful on most other ships if it comes at the cost of armor or weapons. This can be used to balance a faction that would otherwise be too strong (like vaulters, by having weaker ships than lets say riftborn players have a chance to deal with them despite their portal advantage). All factions already have repair and fleet repair modules, by the way. 

The tactic sounds interesting, but for the sake of balance i think it's best if there is only a certain chance to rescue a ship instead of 100%. Else a player would have an too easy time to ground down enemies over multiple battles.

The ground battle advantage sounds fair enough. Could be a unique tactic or a faction trait.

The obliterator restriction sounds unreasonable. Unfallen don't have it and they are supposedly peaceful. If a player wants to play against the thematic nature of their faction, they should have the freedom to do that. It shouldn't be as easy or rewarding as playing according to their nature, but still possible. For example peaceful cravers. Nothing in the game stops you from doing that and people can hack you to turn you pacifist. But most players will prefer to not go pacifist because it's not as rewarding.

Unfallen also have alliance/peace buffs. Still, people can try to play them warlike. By the way, the fact that peace with unfallen is assymetric (unfallen get more benefits, especially that they can annex their allies systems, makes them more interesting. They have many avenues of interacting with other factions, and while alliances are one of their strong points, ultimately an unfallen player can try to win rather than just being the support for someone else. Having a path to victory for yourself is essential to the enjoyment for alot of players, and they don't want to only be a support for someone else. So huge debuffs for not being in an alliance seems to be a massive design flaw. Limiting the freedom of players especially in such a way that they have to rely on AI players when playing solo kills alot of fun in the game.

Hmm fun idea.  I agree with Grilled that there are a lot of balance issues with some of the suggestions but the overall thematic is a great place to start!

They are similar to the Sowers so you could probably just lean into their lore.  They could be an alternate faction of Sowers or more powerful ancestors of them?  What about a boost to fertile planets since they would be "revitalizing" ?  They could easily have buffed anti-depletion, repairing planet cracked systems and converting systems after invasion?

I like the idea of boosting the repair modules?  Those don't seem utilized enough so it'd be interesting to have a faction lean into their mechanic more.  They would have to have weaker offense/defense modules to balance but that opens up the interesting pairing idea you said with an alliance faction?  This presents the strong pairing as a "support" faction without having them completely suck if they were played solo.  They're not meant to be an aggressive civ but can still defend themselves with decent ships that heal.  That could be a good compromise?

I like the idea of resuscitating dead ships but that's super strong if it's 100%.  I'd say maybe a 10% chance or you could maybe do reduced dmg from retreating?  That way they only take the fights they want to take?  I do like resistant to invasion as well.  They could be healing and regenerating so they're hard to invade?  A more defensive race perhaps?

I'd argue that you have to keep all mechanics open to them, including obliterators.  Plus I think you're missing out on the hilarious scenario of them nuking an enemy system to pieces, then invading it and rebuilding it all super fast :D It's it reminds me of Gandhi using Nukes in Civilization.  Sure it doesn't at all go with his thematic but it's fun for players to have these options open to them.  You usually want to leave as many mechanics in for them to mess with I feel like :)

This also goes for your support idea, I'd argue that they have to be self-sufficient.  However, it's a good idea / gameplay hook for them to have incentives to ally with other races.  Like having more support modules on their ships to balance with another player but they shouldn't have to play around that playstyle.  Why can't Healers dominate the galaxy just like Cravers?  Who are we to say they can't play a certain way? :D

This is a really fun faction idea, thanks for posting!