Ah yes, for normal. But to be honest hard mode mechanics really aren't much different just every thing is faster, hits harder and there are no revives. Oh that reminds me. 30 second timers on all deaths before you can be revived. And in all encounters if the relic is dropped for more than a few seconds it wipes the raid.

For the Gatekeeper part everyone inside of the portal will get marked as soon as it is killed and don't forget that the relic guy needs to go in the other portal to cleanse because he will be marked upon arrival (I also tend to use a relic super on the second Gatekeeper to save some time). For Atheon we should not have to call out which side we are on, you can easily see where they are at by looking at your minimap. You need to be standing on either of the sync plates before TIme's Vengeance is over just in the off chance they are teleported to the side that you are already on.