Magic introduced a new card subtype, “siege”, on a card type that itself was also new, “battle”. You can attack battles and try to defeat them. Sieges are special in that you play them on the opponent’s side of the table so you’re attacking your own sieges.
They got the power level just right and that they deserve major kudos for that, that can’t have been easy 👍🏻
Another compliment they deserve is that they were a very good way to represent all planes (together with a couple of other cards from each plane) truly making MOM feel like it spanned all the planes.
But overall I’m not too fond of them.
Flavor-wise the sieges are weird. So you play a card named Invasion of Segovia (for example). What would you think such a card would represent? It represents… the Segovians fighting back at the Phyrexians—both sides of the card are flavored as Segovians doing Segovian stuff vs them.
OK, so it’s called a “siege”. Like Helm’s Deep. And it’s a pro-Segovia, anti-Phyrexia card. So you’d think you’d want to defend it and defend it and defend it, like the Segovians in the story defended agains the Phyrexians. Siege. Simple. But no! You are trying to attack it down to release the sea tyrant Caetus who’ll help you fight the Phyrexians.
So when your opponent plays a Siege, that means you are suddenly forced to represent someone who is invading Segovia (Phyrexians, presumably, whether or not you’d ever put any Phyrexian cards in your deck) and trying to defend the—not defend Segovia, but defend the invading force so they can’t release the sea tyrant or whatever.
The play patterns are fun (and, importantly they’re fun on either side of the table), I just wish the flavor had made more sense. Sieges, for example, would make more sense as “quests”, like “we wanna go find the sea tyrant Caetus and free him” or something.
“But it had to make sense in MOM, a set about the planes successfully defending against the Phyrexians in battle, a bunch of quests wouldn’t make sense there”—exactly! They don’t make sense! They’re not about successfully defending anything. “But double-sided cards are all about ‘before and after’ stories, we needed the flipped-to-side to represent the Segovians victorious because that’s what happened in the story!” Not sure why we’re even playing a game if the outcome is set, but that’s a story for another day.
MOM has many cards that transform into corrupted, compleated versions of themselves. Those are also awesome but what would’ve made a lot more sense would’ve been if the backsides of the battles had been flavored as phyrexia victorius. Your opponent plays a siege set on Theros and if you can’t defend it, they’ll get a phyrexianized version of Polukranos or something. Really putting you in the shoes of desperately trying to defend against Phyrexia.