I know it's really easy to just look at your hand to check the mark meter. Though I feel like it would be useful if there was a little sound that played when it's full. Sometimes I'll be in an intense encounter with a lot of enemies and I might be a too distracted to look at my hand. There should also be an option to disable it completely if it's annoying.
#A sound or jingle when mark is ready to be used
midnight pawn
timid pier
O k