atheon
timestream
shortly after the encounter has started, atheon will randomly choose three guardians to teleport to either mars or venus together. once the guardians have been teleprted they must callout if they are on mars or venus so that a guardian outside can open the portal using the sync plates. one of the guardians that were teleported must pick up the agies relic which should be directly infornt of them once teleported. all guardians inside the portal will slowly gain stacks of the "marked by the void" debuff which will limit the guardians vision more and more as the stacks increase and kill the guardian at ten stacks. the only way to get rid of this debuff is to use the relics block feature. breifly blocking every few seconds is all thats needed to keep the guardians alive.
oracles
one of the guardians on who did not get teleported will have to assume the role of oracle caller. red oracles will appear above the center of the room three at a time. there are six spawns for them: back left(1) back, middle(2), back left(3), front left(4), front middle(5), and front right(6). the oracle caller will get two previews of the oracle order and must call them out because the oracles will spawn inside of the portals. the team inside must then break the oracles in the order they were told. after three sets of oracles are destroyed, all guardians will recieve the "time's vengeance" buff which will allow them to damage atheon as well as giving them significantly reduced ability cooldowns for thirty seconds
dps
most fireteams do damage from the stairs infront of the portal that the guardians are comming out of or on the floating platform in the middle of the room. due to the enhanced ability regen most guardains will be able to use two supers in one dps phase. if the fireteam is not able to kill atheon in four dps phases then this will result in a wipe.
ensemble's refrain
to complete the "ensemble's refrain" challenge each guardian that was teleported must break one oracle during every set. when completing the challenge on master all guardians are guaranteed the "corrective measure (timelost)" machine gun.