So boss encounter:

What I do is usually split the group into 3 teams: Mote Team 1, Mote Team 2 and Builder Team.
At the start of the fight, clear ads and kill the Angelic. This opens up the boss's crit spots. When the right spot is open, Mote Team 1 should invade together by jumping into the orange portal.
As the portal is opened, a sect of land will have particle effects on it and vanish. Stay out of it while it is vanishing or you will be killed. A Cyclops will also spawn on the side the portal was opened on. Kill it ASAP. While all this is happening ads will spawn. Kill these ads before they sacrifice at the relay and drain motes/cause a wipe.

After ads are down, building team has some time to rebuild lost sects.Tether from a relay to a node to rebuild a sect.

When Team 1 has 15-18 motes, they should call for a pull on their side(pull left/right). Team 2 should hop into that portal together and a Cyclops will spawn.

Around this time, barriered ads will spawn similiar to the 2nd encounter. Only people with enlightened can break their shields. Similiar to 3rd encounter, depositing motes gives you enlightened. After clearing ads building team can rebuild.

After Mote team 2 gets 15-18, pull right. If the prompt says "The tether pulsates with ___ energy' , that bank is full. If it is not full, Team 1 must invade right again and fill it asap.

If it is filled, Team 1 should shoot the knee crit and invade the blue portal. This repeats until both banks are full with 30 motes.

In summary, the lead up to dps goes like this: Pull Left Left Right Right or Right Right Left Left, with Team 1 and 2 alternating invades.

If you do this correctly, a wave of ads and Angelic should spawn, and the boss should have a node near its chest. Based on the node's colour, a team of 3 should tether from that respective tether to the node to break it. One person should be in reserve to help the tethering people. Others should move to the opposite side.

Once the first node is broken, everyone should swap sides, and tethering team should break the node using the other tether. Note that there is a visual glitch causing it to always appear blue but ignore it.

After the second node is broken, DPS phase begins. Go to a Bubble/Well and begin DPS on the boss. You can use oppressive darkness/hunter tether to debuff him.

After this, you have some free time to rebuild before you repeat the whole process. Rinse and repeat until big boi is kill.