Well, let me try and cover a lot of related questions too.
Every kingdom is associated with a traitstone. That traitstone determines what kinds of traitstones you expect when you play a match “in” that kingdom. That means:
- Explore matches.
- Challenge matches.
- PvP/Guild Wars/Arena matches (they happen in the home kingdom of the defender.)
GoWDB has a Traitstones page here: http://gowdb.com/extras/traitstones, it can show you which kingdoms are associated with each traitstone. Conveniently, it also lists which troops use each traitstone. The in-game UI can help you find the kingdom for a traitstone, too.
Here’s how they drop.
- Celestial traitstones will ALWAYS be eligible for every kingdom.
- The Arcane traitstone associated with the kingdom is the ONLY traitstone that will drop in that kingdom. (For example, Arcane Swamp is green/blue, but Merlantis will NEVER drop the blue Arcane Stoic traitstone.)
- EITHER color of the kingdom’s Arcane traitstone will be the eligible minor, major, and runic traitstones. (For example, Merlantis is Arcane Swamp, so it can drop both Minor Nature and Minor Water traitstones.)
- Explore matches apply a bonus multiplier to the drop rate of Arcane traitstones and Celestial traitstones.
So, in terms of farming:
- If you want a specific arcane, you MUST be in the kingdom associated with that arcane.
- If you want arcanes, Explore is the best mode.
- For minors, majors, and runics, if you want a specific color it’s best to pick a single-color kingdom and do challenges, since fewer arcanes/celestials will drop.
So, for Pharos-Ra, to be specific, it needs two Arcane traitstones and each has two potential kingdoms:
- You need Arcane Spirits, which can come from Glacial Peaks or Khetar.
- You also need Arcane Skulls, which can come from Darkstone or Dhrak-Zum.
It doesn’t really matter which from those pairs you farm, but since each Explore rotation is different there’s usually one that feels easier due to the rotation. For example, I prefer Maugrim Woods for Arcane Swamp farming, because Merlantis troops use a lot of Submerge and that slows down farming.