Another experiment with Portal on instant/sorceries.

A bit of a flavor/theme thing here too: Spells that reference and feel like a place, that transform into creatures with the feel of that place or that would come from that place.

I could see this maybe having a "return to battlefield transformed" thing on 1st side even.

This and Glory of Elysium look like channel.

It would be cooler if the portal mechanic was a little more involved. I'm thinking e. g.: Flavor the spell as a forecast to the creature and make it:

> Portal (Exile this spell as it resolves. You may cast it transformed from exile for its portal cost.)

Rules issue: The backside will not return itself to the battlefield unless it also contains the "transformed" since an instant cannot move to the battlefield.

I had wondered in the back of my head if "exile this spell" might be a spin on/part of this mechanic.

I see what you're doing with that version, that's a possibility, more in the direction of an optional effect on top casting the spell normally, and it allows you to get both effects.

The nature of the current version is more that you're not required to cast the spell conventionally, the creature is an alternative option and it's an alternate mode of the card. Simply putting a card onto the battlefield is more direct, but kind of ambiguous and unlike casting a card. That does open up potential rules issues in application.

Your version seems to be more involved, less "direct" feeling, but has less potential rules issues around cardtype, while making it explicit that you are still casting a spell.

It's also looking like "exile matters" is replacing "color matters" as a theme in the set.