According to some Reddit threads discussing the JP Anniversary streams, there’s going to be a new system for grailing servants up to Lv120. Not only that, but at max level, they’ll gain extra passive abilities, and one that they showed up was a patently ridiculous 100% NP charge on turn 1.
(Edit: It’s actually a 20% charge, the 100% shown happened with a non-MLB Scope)
What I’m saying is, hoard your grails people. You’re going to need them…
So, as far as I could gather, you will need the following:
-Servant coins, which you’ll get from bond levels and copies of the servant you pulled
-Grails, which is a limited resource
-Tons of QP and Embers to actually level your servant
The passive skills apparently don’t require Lv120, but they may require higher levels to unlock. These passives also have to be unlocked with coins, and then raised like normal skills.