Quote Originally Posted by Angry_Evil View Post
snip.
Ruinla (should be Ruinra) is Ruin II, and Ruinja is Ruin IV, so the upgrade is just how it was in Stormblood, except now a trait is learned at lvl 74 which guarantees Ruin IV process when a pet uses an action (currently it's just a percentage chance). You can stack the Ruin IVs up to 4 max (with the new charge system) so they are available to use whenever you want to weave them in to your attacks.