#x cost

[magicjudge]

Welcome back Charlotte! I've got a question about how Altered Ego and the new ravenous ability interact. Specifically, if I cast Altered Ego with X>=5 and have it enter the battlefield as a copy of a creature with ravenous, do I get to draw a card? Or is ravenous linked to the printed X cost?

You won't get to draw the card, or get extra counters. As Altered Ego enters the battlefield, it stops being Altered Ego and becomes whatever creature it's copying. It wasn't cast as that creature, though, so the X for that creature's own abilities is 0.

Note that this is different if you copy a spell with Ravenous while it's on the stack. In that case, it will keep the same X value.

[magicjudge]

If I cast a spell with X in its cost, such as torment of hailfire, using bolas’ citadel, can I choose to pay life for the value of X? Or will X inherently be 0? Thanks!

Whenever you pay an alternate cost to cast a spell, such as with Bolas’s Citadel, you can’t choose any value for X in the mana cost of the spell since you’re not paying the mana cost. In all of these cases, X is forced to be 0 and so Bolas does a pretty poor job of making these spells do anything.

[magicjudge]

Quick question! If I have Epic Experiment in my graveyard and I cast Past in Flames, will I be able to choose what I want X to be, as I figure it would be, or would it be 0?

Past in Flames gives Epic Experiment a flashback cost equal to its mana cost, i.e. XUR. When you cast Epic Experiment from your graveyard, you’ll choose the value of X just like if you were casting it from your hand.

[magicjudge]

Yes, the new Nissa will survive if you control Oath of Gideon and cast her with X=0. She’ll enter the battlefield with one loyalty counter on her due to the replacement effect from Oath of Gideon.

[magicjudge]

How does Nissa, Steward of Elements interact with Walking ballista? If she has X loyalty, does Walking Ballista come in on x/2 counters?

If Walking Ballista enters the battlefield without being cast, then X has no value and therefore it enters the battlefield with no counters on it and promptly dies the next time state-based actions are checked.

Walking Ballista doesn’t care about how many loyalty counters Nissa has. Walking Ballista’s CMC is 0 when it’s not on the stack. It doesn’t magically take on another value just because of Nissa’s ability.

[magicjudge]

Two part question: If I play a prototype portal, and use the imprint to exile a walking balista, is the mana cost for it divided due to the balista having XX as it's mana cost? (so if i payed 2 mana and taped prototype portal, the mana on the balista is 1/1 instead of 2/2) (sorry if I'm wording this poorly) Then, if when the balista comes onto the battlefield I already have a panharmonicon on the field, does it get double the counters on it?

X in a card’s mana cost is always 0 unless you’re casting that card as a spell. That means that Walking Ballista’s converted mana cost is always 0 when it’s on the battlefield or in exile. 

Since Walking Ballista’s CMC is 0 while it’s exile, that sets the X in the cost to activate Prototype Portal at 0. You can’t choose a different value. The token copy of Walking Ballista will enter the battlefield with no counters on it and die to state-based actions unless some other effect increases its toughness (and no, you can’t activate its 4 ability in time to save it.)

[magicjudge]

If casting By Force with X = 2, can I have it target the same artifact twice?

No. When you cast By Force, you have to target X different artifacts. If there aren’t 2 artifacts to target on the battlefield, then you can’t cast By Force with X=2.