Hard time coming up with good flavour for this. Was originally going to cost this

Kind of funny how white is doing the heavy lifting here. Red has lands covered. But that comes with the reminder that this is probably undercosted, since straight land destruction never costs three mana nowadays.

Considering that White has yet to destroy a Planeswalker outside of one mass removal spell, maybe 'Exile target nontoken permanent' makes sense with the increased cost of ?

No, this color combination can't straight up destroy planeswalkers or creatures

I think red being alloed to destroy a planeswalker on this two-color card is a bend of red burning them to death a la Lightning Bolt rather than a break. That being said, RW hasn't gotten direct planeswalker removal to my knowledge, and my thoughts were based off of Terminate and kin, which are already in black which kills planeswalkers and creatures. Green's noncreature removal would still work if you wanted to back to that color combination. Actually, thinking about this further, I can't recall white getting any planeswalker removed since the card type, which makes it harder on red to be the sole justification to kill a planeswalker from a destroy effect rather than damage.

Well I figure it’s a straight downgrade from exile target permanent.

Also white can targeted destroy any kind of creature, so long as the target is restricted to a subset of all creatures, such as nontoken creatures.

I didn’t think about walkers. 2GW would probably be better, but I don’t have a good flavour for it.

I mean BW fits the pie better, but the point of the nontoken clause when I designed this was to justify a more novel card. BW can already do this, but better.