What if there was a plane of just air, with no land or resting liquid water? All creatures would have to have flying. Giving every creature in the set flying is pointless in the set and breaks the color pie for other sets. So, how do I capture the concept of flight in a world where everything has some form of aerial mobility? Maybe a special flight? Soaring (above flyers) seemed right. This is my first attempt at trying to capture the concept that I'm going for. To be fair, I have no idea why I thought instants and sorceries would be a good choice to start to activate soar.

It's a very good word for the ability. I'd split the activation out, mind you - so while this creature maybe cares about instant/sorcery, others might not.

Bizarrely; this can't block flying creatures. That might be appropriate for some soaring creatures, but feels weird on this one - which explicitly says it can dive back down.

I'm definitely not oppose to making different triggers to soar, should I ever move forward with this idea.

Yeah, the drawback of not having flying show up at all makes for weird flavor outside of the plane.

Un