What the achievement asks
Reach the Legend of the Multiverse friendship rank with Soridormi. Ten points, account-wide, and it awards a title.
The quest at the end that nobody expects
Reaching maximum friendship does not award this by itself. Go back to Soridormi at the Temporal Conflux and take Realized Potential. Handing that in is what gives you the title and the achievement.
Players regularly cap the bar, see nothing happen, and conclude it is bugged. It is not: there is one more quest.
Where the reputation comes from
| Source | Roughly |
|---|---|
| Taking part in a Time Rift | 250 |
| Killing the rift's final boss | 250 |
| Earning 7,500 Temporal Essence in a rift | a further 500 |
| The weekly quest | 1,000 |
| Each boss in Dawn of the Infinite | 300 |
One active rift a week plus a full clear of Dawn of the Infinite is roughly 3,900 a week, which is where the two-to-three-week estimate comes from.
The fast route, now that the rifts are quiet
Dawn of the Infinite has been split into two heroic dungeons that you can queue for in the dungeon finder, and each boss still pays 300 reputation. Chaining the two of them is faster than waiting on the hourly rift schedule, and it does not depend on anyone else turning up.
That is the route to take if you are doing this after the fact. Rifts were the intended path and they are still the best source when one happens to be running while you play, but they are no longer the bottleneck they look like.
While you are running rifts anyway
Every rift you enter for this also feeds Just Following Chronological Orders, which wants a hundred tasks, and puts you in the room for Collapsed Reality, which needs a crowded rift and is the hardest thing in that branch. Joining a raid group in the group finder before the hour helps all three at once.
Where it fits
One of twelve under Oh My God, They Were Clutchmates, a piece of A World Awoken.