If this has been answered elsewhere, apologies in advance....

If a character has a power that says "can use", when fighting another character, does the OTHER character have to have that particular power showing on the dial? As an example...

Thorbuster has a power that says:

"When he attacks a character that can use Invincible, modify damage +2."

Can he use this ability if the other character is using Invulnerability at the time?

Thanks in advance.

Is this about the crowbar?

My guess is crowbar and the Armorknights.

No. Invincible and Invulnerability are two different powers completely.

It the target can use Invincible and also can use Invulnerability it would work though, and it doesn't have to be showing through the dial specifically. It can be a power the character "can use" through another game element.

The target does not need to activate that specific reducer for the effect to trigger if that is what you are asking? The fact they "can use" it is enough.

Hope that helps. Not entirely sure what the question is but that covers some angles

This is why its better off to quote the actual effects from a real-world scenario, instead of vague allusions. Its difficult to tell exactly what you're asking here.