Brethren Missions 1-3
The Brethren series of missions in Solar 2 have you working as caretaker of the universe, looking after planets that need your protection in order to convert them to your way. All three missions have different strategies to use, however, having dual star or tri-star system with max life saved as one of your spawnable systems will be helpful.
Brethren Mission 1
For this mission, you will need to protect a target planet that has no life on it. In order to do so, spawn your max life system, consume one of the planets and pick up the target planet, preferably within one of your inner orbits to keep it protected. All you need to do is keep it alive for 60 seconds while asteroids fly at you from all directions. With this method you can pretty much stand still, maneuvering slightly to pick up some of the roids to gain mass on the target planet.
Brethren Mission 2
For this level you need to take your solar system and at least 4 Life Planets through an obstacle course, reaching the target beacon without colliding with any objects whatsoever, beyond spaceships or their lasers and missiles that is. The best way to do this is take your time and travel with 4 planets only to avoid dealing with a wider berth more prone to collisions. Completing this level with 10 planets will grant you a special congratulations.
Brethren Mission 3
Finally, in the third mission, it’s time to sacrifice your followers to the celestial gods. In this case you will need to take six of your orbiting planets and drop them into the nearby Black Hole. Spawn your max life system before picking this mission up and work your way from the outer orbits inwards. Once you get to orbit 5-6 however, gravity begins to endanger your stars, so it’s a good idea to pick some new planets up after dropping off the first 3-4.