Gideon Blackblade / Valkmira interaction. [Fixed]

Asylamb

I was pretty disappointed with how easy it is to cancel Prevent Damage effect provided by Valkmira, so I decided to pair it with Gideon Blackblade whose L3 also provides PD. Yet the combo proved to be ineffective:
1) When Valkmira's PD un-triggers, it also removes PD provided by Gideon's token. So, question #1, is Valkmira supposed to remove Prevent Damage from other sources? IMO, it shouldn't.
2) After PD was removed by one of Valkmira's triggers, at the beginning of my next turn it returns to my creatures (they get PD back), but not to the PW. So, question #2, why my PW doesn't have Prevent Damage while having 2(!) sources of PD on the board (Valkmira and non-disabled Gideon token).
Hexproof from Valkmira works fine, so far.

Tremayne

@Asylamb - you are referring to the rare support card, right?

Because the card specifically states that “Your creatures and Planeswalker lose...” so I would think that covers question 1 above. Can you recall a combination of cards that has a similar wording but with a different result?

Question 2 definitely sounds odd.

Asylamb

@Tremayne yes, I refer to Reidane (Rare White God)'s front side that gives you and your creatures Hexproof and Prevent Damage. I found that interaction (Valkmira removing both PD effects) kinda disheartening but understandable.

Can you recall a combination of cards that has a similar wording but with a different result

Not really. I just remember a situation (I think it was either one of Oath of the Gatewatch nodes or a BFZ Story Mode nodes) when an ability stripped my creature of Vigilance, but that Vigilance was provided by an external effect (High Alert), and the creature got the evergreen back right after.
So, I would hope, that once PD by Valkmira turns off, PD by Gideon turns it back on.
But the real problem is that it never turns back on.

Tremayne

@Asylamb - well, you know with all the bugs in MTGPQ sometimes established and “correct behaviour” turns out to be a bug, when convenient for the devs. (Official rule changes is of course allowed)

So perhaps the High Alert case you seem to remember, is actually a bug. Nevertheless, I’m pretty sure that effects that removes something has priority over effects that grant that same something. I can’t recall if that is a written rule (or just a hunch), but perhaps that is just implied. 

I think it would be a good subject for another thread, to get the devs. to elaborate on.

Asylamb

I don't seem to remember it. The node had an objective of playing X or less creatures, so I was using a Tamiyo deck with TSN, Divine Visitation and High Alert. And the opponent either had the Loyalty ability to switch Defender/Vigilance with no-that, or had Void Winnower in the deck (I think option 2).

Stormcrow

Losing prevent damage like that is pretty consistent; if you provide Razia or Underrealm Lich with Prevent Damage from another source, they will still lose Prevent Damage after preventing damage. So that part seems consistent. Not getting it back is a bug, though.

Asylamb

I think that if the "loses Prevent Damage" effect doesn't specify "and can't get gain Prevent Damage" like Shadowspear does, multiple sources of Prevent Damage should work separately and Valkmira should remove Prevent Damage from creatures but Gideon should still give Prevent Damage to PW.