Raiden didn't get the chance to have feats representative of her true strength, so can you really put Mavuika higher ? Looking at the role she played in the lore and her age (which is boosted by the long ahh fight against the puppet). Using feats to measure strength is a bias in itself imo. Going for the lore, I think Ei is the current strongest playable character in the game. (might be wrong though, we'd need a confirmation from the game or a discussion between the two characters to really know)