You are gated to 120 crest a week, for each type, doing the 8 m0 gives you 80 creasts the last 40 are 4 normal bosses, or 4 weekly activities or 4 weekly quests… also when you reach the limit on a higher tye of crests it becomes lower ones, so if you made all the m0 jump to m2 until capped on wyrm and get the drake ones instead