My question is, since Doom's special damage power isn't an attack or breakaway, and since his power doesn't say "can't be rerolled", could Mxy's replacement die be used to replace Doom's d6 roll?

Mxy's trait says:
"Whenever any dice that can be rerolled are rolled (including as part of a 2d6 roll), you may remove the d6 from this card and replace one of those die results with the rolled result from the d6 removed from this card."

Doom's damage power says:
"Dr. Doom can use Outwit and Perplex. When Dr. Doom uses Outwit, he can use it normally, or you can roll a d6 instead; on a result of 4-6, counter a power possessed by a single target opposing character anywhere on the battlefield."

Yes, Mxy can replace any die roll that can be rerolled, which would include breakaways, attacks, and Doom's.

The limitation of re-rolling only Attacks and Breakaway rolls is specific to Probability Control.

Wow, it's been a long time since I've looked at that Doom... how would that attack power work with the new EE?

Kneel Before Doom!: Dr. Doom can use Energy Explosion, but deals damage equal to his damage value to the target of the attack. Characters adjacent to the target are dealt damage normally.

ENERGY EXPLOSION RANGE: Make a range attack, and all other characters adjacent
to an original target also become targets. Hit characters are dealt 2 damage instead of normal
damage.

So if the adjacent figures are also targets, would they each take his damage value as he "deals damage equal to his damage value to the target of the attack" or would the power be automatically updated to "original target" for any sweeping errata that I'm not seeing?

This Doom's EE has actually already been discussed. Yes, it would be "original target". There is no general errata for EE, but there is plenty of precedent for how special EE powers.

Even if he worked the other way, he'd still be pretty much unplayable. If you want insane area damage, just use Hammer.

I'd like to further splash-damage this thread by adding Punisher and his filthy non-EE EE.

Never bothered to look at those two side-by-side, but now that I have, I feel really bad for poor Frank here. I mean, I guess he can shift and stab people if they get close? But Hammer can do 5 damage to each target, with an attack value of 13. He's super ridiculous.

By comparison, Frank still has a few things going for him: he has an 8 range, he's still effective when there is only one or two opponents he's shooting at, and he's a common. The good news is that neither of them are Unique or Prime, and they're each only 50 points. Whereas ol' Doom is a whopping 200.

Well, no primary attacker that's that old can stand up in a modern game without a LOT of help... even then, they aren't worth their points, but they are sometimes a lot of fun to play and see someone's face when they've never seen it and don't know what to expect.
Heck, I just played Chaos King for the first time yesterday and really scared one of my opponents (even with his 10/17 stats).

And for what it's worth, I wasn't sure if intent or recent errata to other figures would the precedence over the powers as written. Actually, along those lines, when would the power as written override the seeming intent?

To clarify my point, let's compare:



A couple rulebooks after he was made, "optional" was no longer a thing so as written, he has to use his damage power whenever he uses a ranged action (RANGE in current terms)... but why would he work as written while other figures (not just Doom, but I can think of a few others like special regens) work as they originally did (intended) instead?

Nothing about that Iron Man is affected by recent rules changes. If they had wanted to "fix" him, they had their chance to issue errata years ago when the change was made. Doom has to account for changes to EE (like every other figure that has ever had a modified version of EE), which we have plenty of precedent for. There were plenty of EE powers that got errata'd with the new rules, which make it fairly easy to apply the intent of the changes to older figures.

In that example, it was years after the fact that "optional" was removed so they didn't retcon retired figures that I've ever seen or heard of. This is one of several examples I've seen over the years that suffered from rule/verbiage changes... It's just the only one that comes to mind right now.
So if there was another example that was errata'd when the rules changed, would that be enough of an example to override the ruling and treat it as if it's also errata'd?

I mean this seriously... where is the line of what is treated as written and what is treated as it was before?
Although in all fairness, as retired elements, WK will never rule on it so it may be up to the judge to decide... which would probably be your answer.

Honestly, your line of thinking here is way off base. Its not about there being a line and selectively deciding if something should be errata'd. Its a matter of things needing to be errata'd to work properly with the new rules, and looking at existing errata for precedent.

Iron Man functions perfectly fine within the rules. He just sucks. You can make the same argument for all those old figures that have Super Strength and HSS. Or those figures that were given EE and PB together.
Or about a million other things. See how quickly that becomes a slippery slope?

Energy Explosion has completely changed in functionality. Nearly every old power that has a modified version of it has to be interpreted individually under the new rules. After the 2017 changes, there were more EE-specific erratas than anything else, and there was a very good reason for that.

Comparing Iron Man being affected negatively by rules changes but still functioning fine, to Doom needing errata to work with a major overhaul of a standard power, is pretty much the definition of an apples-to-llamas argument. We're talking about two, entirely different and distinct concepts here.

As I've said plenty of times, when big rules changes like this happen, some things get better, some things just get worse. It happens. The important thing is not that the relative power level of individual pieces remains the same (that's actually the exact opposite of the intent of rules changes a lot of the time), but that everything functions consistently.

I can appreciate that. The hardest part, of course, may be a judge's interpretation in a game (accurate or not) as to the rule change and how it would interact with said power. I may have to look up old figures here before I play them if they have power modifications like this and forests it to the judge beforehand so they are aware.