Maps found in your Maps have +1% chance to have a special Implicit Modifier for each different Map you have Favoured 
Prevents any Favoured maps from dropping. It is unknown if it disables Unique versions of Favoured maps. This does not affect certain Map Rewards such as those from Delirium rewards.
Shadow Shaping can be used in several ways:
- The player can pick between two adjacent maps, stack 100% chance to drop an adjacent map (via Wandering Path), and favourite all other connected maps. This will guarantee that a random monster in your map will drop an adjacent map. Map Bosses also have a natural chance to drop an adjacent map. This allows infinite sustain of maps between two maps.
- If the player has less than 4 Voidstones socketed (therefore at least some maps are below T16 on the Atlas), Favouring all but one map in that tier will guarantee that one map to drop at the given tier. For example, at 2 Voidstones and 12 Favourites, it is possible to block all but one each of a T14 and T15 map.
- The Keystone appears to randomize dropped maps until they are not restricted by the Favourite map ban. This means that the adjacent map drop mechanics can sometimes drop maps which are not adjacent, but in the same tier as the adjacent map . It will never drop the banned map.
As of version 3.18.0 it is located near the center of the atlas passive skill tree, to the upper left of the central "Kirac" wheel.