To gain access to Shard's Landing, you need to complete T10 (Devastation) progression, and also Plane of Time (potimea) Quarm kill. Kill Quarm in potimea, and then loot one of the shards from Time Orb, to get the flag. You will then be able to zone into Shards Landing.
Also, after getting the flag, you can speak to Brig thakan in potimea to be offered an upgrade on your Underfoot Touched Hero Stone Rk.9 to Rk.10. Be warned, it's expensive!
(Quests and Progression for shardslanding)
Work in progress