Could outright target any creature. Spells that affect only a certain tribe are often dead to most players. It's usually better to have cards that have a small effect but become significantly better played with the right cards.

Possibility:

> Target creature you control cannot be blocked by creatures with power 2 or less this turn.
Up to one target Rebel creature you control cannot be blocked by creatures with power 2 or less this turn.

So you get the effect a second time for free if you play the tribe, but if you don't (or have lost all Rebels to removal/trades), you still get the effect once.

I don't think it would even need to cost more since you erred on the high side with two mana.

Practically there is not much gain to this being an instant. Making it a sorcery simplifies processing without sacrificing any substantial depth of gameplay.

Good points and an interesting recommendation.

I have a problem with making dead cards. I would happily make them all like this except I always worry I'll have to up the rarity to compensate for wordiness.

May not block / may not be blocked are annoyingly a colour difference. But only for flavour reasons, so an acceptable bend; especially as this is now usable for everyone. It might be a bit too good for its cost, it's gonna be VERY fiddly to work out how to best use it.

I'd also suggest making it a sorcery? You're only ever gonna want to cast this in main1 anyway; so why not make that more obvious?

(I mean, yes, techincally you could cast this after you declare attackers but before blockers are declared - but if you change your mind based on which attackers you declare, then something VERY strange is going on.)

oops, secret said that too! I meant to add that, but forgot.

it synergizes well against the main enemy of rebels this set: advisors. RB vs WU seems very reasonable, and advisors aren't exactly beefcakes lmao

> be a bit too good for its cost

Red Ghostform this isn't.

As I consider making daunt a thing in Arnath which is thematically really similar to this (down to Rebel tribal), and basically created the wording, I'm going to nap the effect: Forced Entrance. :)

Okay this is epic.

I know that isn't what you meant... but yes; this really would be a moderately good candidate for being an epic (recast every turn) spell :)

Really?

I guess as your board gets stronger it would be more useful... but the opponent could also do the same, and Daunt relies on that not happening. In the sideboard against the right deck, maybe?

I suppose it is a very reusable ability, like life gain and damage and etc.

Also i'm pretty sure nobody is out to recast commons exclusively... I'm sure flashback, buyback, jumpstart and the like would love to, but this could actually cuck yer game kinda terrible.