Necrotic Ooze + Callous Oppressor

[Star|Scream]

What exactly will happen if Necrotic Ooze is tapped to use Callous Oppressor's ability? Would you need to have an oppressor on the battlefield as well?

I apologize for not putting the card info in, I do not know how to use card tags on this forum.

[cdr]

Card tags are .


Callous Oppressor 1UU
Creature - Cephalid
You may choose not to untap Callous Oppressor during your untap step.
As Callous Oppressor enters the battlefield, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as Callous Oppressor remains tapped.
1/2


What exactly will happen if Necrotic Ooze is tapped to use Callous Oppressor 's ability?
Since no choice was made for the ability, the ability can't do something involving that choice. Since you can't choose a target, you can't activate the ability at all.


Would you need to have an oppressor on the battlefield as well?
No, that's not how Magic works. A choice made for a card is only for that card. When an ability uses a card's name in its text, it only means "this card".

706.7. If a pair of linked abilities are copied, those abilities will be similarly linked to one another on the object that copied them. One ability refers only to actions that were taken or objects that were affected by the other. They can't be linked to any other ability, regardless of what other abilities the copy may currently have or may have had in the past. See rule 607, "Linked Abilities."

706.7a. If an ability causes a player to "choose a [value]" or "name a card," and a second, linked ability refers to that choice, the second ability is the only ability that can refer to that choice. An object doesn't "remember" that choice and use it for other abilities it may copy later. If an object copies an ability that refers to a choice, but either (a) doesn't copy that ability's linked ability or (b) does copy the linked ability but no choice is made for it, then the choice is considered to be "undefined." If an ability refers to an undefined choice, that part of the ability won't do anything.

Example: Voice of All enters the battlefield and Unstable Shapeshifter copies it. Voice of All reads, in part, "As Voice of All enters the battlefield, choose a color." and "Voice of All has protection from the chosen color." Unstable Shapeshifter never had a chance for a color to be chosen for it, because it didn't enter the battlefield as a Voice of All card, so the protection ability doesn't protect it from anything at all.

Example: A Vesuvan Doppelganger enters the battlefield as a copy of Chameleon Spirit, and the Doppelganger's controller chooses blue. Later, the Doppelganger copies Quirion Elves. The Elves has the ability, "{T}: Add one mana of the chosen color to your mana pool." Even though a color was chosen for the Doppelganger, it wasn't chosen for the ability linked to the mana ability copied from the Elves. If that mana ability of the Doppelganger is activated, it will not produce mana.


201.4b. If an ability of an object refers to that object by name, and an object with a different name gains that ability, all instances of the first name in the gained ability should be treated as the second name.

Example: Quicksilver Elemental says, in part, "{U}: Quicksilver Elemental gains all activated abilities of target creature until end of turn." If it gains an ability that says "{B}: Regenerate Drudge Skeletons," activating that ability will regenerate Quicksilver Elemental, not the Drudge Skeletons it gained the ability from.

[Star|Scream]

Wait, didn't you just write that it could be used?

Can someone else please verify?

[cdr]

I had an incorrect answer up for about 60 seconds, then I double-checked my gut answer. The ability cannot be activated.