A couple of questions with what some has said:
I seem to remember that if you deactivate Lampstand on a turn, that you can't activate it again.
When the opponent decides to deactivate the artifact, he/she cant reactivate it.
Does that mean that if some one deactivated Artifact A, activated U&T, they can't reactivate Artifact A after U&T finishes?
2)
The confusion here comes from the idea that when you activate an Artifact, you first deactivate it.
So if you don't need to deactivate an artifact to reactivate it, then shouldn't Priestly Breatplate stay on the priest each turn since it remained active the whole time (I know I'm reaching but I'm still fighting that battle
).
Urim and Thummim
Type: Artifact Brigade: None Ability: None Class: None Special Ability: On activation, if you have a High Priest in play or set aside area, look at one opponents hand. You may then deactivate this Artifact and activate a different Artifact.
Artifact A
Type: Artifact Brigade: None Ability: None Class: None Special Ability: When activated, it becomes any artifact of your choice until it is deactivated. Cannot be negated.
Priestly Breastplate (Priests)
Type: Artifact Brigade: None Ability: None Class: None Special Ability: Negate all ignore and repel abilities on Characters and Enhancements. May be placed on a good High Priest when activated.
