Cactus Game Design Message Boards

No on both. There's a rule that an Artifact that is deactivated or otherwise removed cannot be reactivated during that turn.

So when during your prep phase do you have to activate a new artifact? Lets say i have rams horn up from my last turn, can i play some enhancements cbi then activate a new artifact?

Yes, an artifact with an on-going or triggered ability remains in effect until it is deactivated. If you have an artifact with an activated ability and you choose to activate that ability (i.e Holy Grail) then you have made the decision to keep that artifact active for that turn (barring an ability letting you activate a different one).