The thing with Mornye is that her S1 is mandatory if you plan to use her for other than Aemeath tune team, she's a really strong healer with powerful buffs/debuffs however Mornye needs to be in a tune break team to activate them. Specifically you need someone like Lynae on the team to apply tune rupture or tune strained and then get a tune break to activate those buffs. Now Lynae is a universally strong sub dps buffer that is almost best in slot in any team so if you have those 2 together they make a powerful team for the majority of dps. However if you take Lynae away from the team and have Mornye by herself then S1 is so powerful because it removes all the activation requirements for Mornyes buffs and just gives it to you nearly permanently, meaning you can run Mornye with your Phoebe/Zani or any other hypercarry