Another thing that makes me think that is the fact that the "Clarification" in the CRD is the same wording that is already on the card; what was "clarified"? Was the author of the CRD supposed to clarify it to say "each of your Shadow phases...", but accidentally copied the existing text?
The thing clarified is in the second part of the text where on the card says: Discard this condition, whereas the cards itself is a possession.
I think that wherever it says "each Shadow phase" it means each Shadow phase. If that makes certain cards too powerful, that's a mistake with the card. Some kind of action should be taken, but before we condemn every card with the phrasing "each Shadow phase", I think we should list those cards and see if the required action should be an errata of 1 card or complete change of phrasing.
Note that
Spurred to Battle says THE shadow phase, which makes me think it means the shadow phase of the player who played
Spurred to Battle.
So, not counting
Spurred to Battle, these are the cards I found with the phrasing "each Shadow phase":
Vile Pit (
17C118)
Breeding Pit of Isengard (
15U188)
Dimrill Dale (
1U350)
Great Chasm (
2U118)
Also note that 3 out 4 of those cards are sites and there is no problem with their text, which leaves only
Vile Pit. If anyone else finds any other card with the phrasing in question, please post it.
As for the
Vile Pit, I think the wording should be changed to "your Shadow phase". It is indeed strange that a card would allow you to play minions outside of your shadow phase and I don't think that was the intention, especially given the fact that the card is common while the effect is unique.