Highfather pacts at beginning of game. I have Wolverine/ X23 Duo as highest point figure. Turn 1 I split into DoFP Wolverine and MM X23. I select that the pact is with X23. I now have a great Wolverine ready to tear it up.

Everybody good with this?

It helps to quote the power when asking a question.
That being said, I'm not sure if they've already ruled on this, but what you ask looks like it would work to me...

I see it being with whichever is the highest point character. If they are both the same point cost, I think the player who initiated the pact chooses x23 or wolverine.

Here's a ruling on The Pact and replacement characters:
http://www.wizkidseventsystem.com/bb...php?f=3&t=3543

I'd still opt to choose to use Highfather for the Takion replacement-- if The Pact will be completely lessened in effectiveness as a strategy, overall-- as he serves as a decent support piece in his own right.

But that's primarily about other figures added to Highfather's team (if a Takion comes in from Hope, I imagine), not if the target of the Pact splits. It's locked or I'd reply to it... does anyone want to ask them the question (which is pertinent)?

The Pact doesn't say what would happen with replacement figures and the PG says that when a figure Splits, only one of them would have any game effects from the Duo applied to them and the active player chooses which one gets it. While that's normally intended for Relics/Resources, it would make sense that the active player (the one Splitting) gets to choose which one has the Pact assigned to them.

That's not what the PG says. And it isn't just for resources/relics.
It applies to all sorts of effects...feats, ATAs, etc. One that comes to mind in the vein of this is Mortal Wound (Sabretooth).

The players guide says:

Replacement Characters
Game effects that are applied to a character prior to replacement are applied to the new character accordingly. If the replacement results in multiple new characters, then the game effects are distributed as decided by the characters‘ controller.

So it seems ok to me to apply the pact to X-23.

Thanks for quoting that.
That is not saying that only one gets any of the effects.
Say that my Avengers Prime has the Avengers Heroic Age ATA, has been hit with Mortal Wound, and has picked up Mjolnir. When I split, I can give the ATA to Cap, the Mortal Would to Thor, and Mjolnir to Iron Man. I don't have to pick one guy and give everything to that one guy.

I'm sorry I didn't say that perfectly, but I was referring to the intent that was being asked and yes, I know it applies to everything. The active player gets to choose who gets what when they split so the one splitting could choose which one the Pact is on... that's the point I was making.