How about this, the higher the meter, the more damage he/she does. This would require the player to rely on good reads and patient play when their meter is low and it would teach them not to just spam fatal rushes when the meter is high but actually use it to their advantage
Was more on the lines on Ex: This character can use the meter for his own special quirks, however the disadvantage for something like that is that he/she won't be able to use Fatal Rush/Break Hold etc. because he/she will have to build meter again to even be able to do it, so the special quirk from the character has to be used intelligently.