Well the Nexus gives us flexibility at least, choice. On top of that, it only increases the weapon damage, it's the equivalent of the Animus. Upon reading the patch notes, there's mention of getting back your scroll for the next stage of the relic so I reckon it will be the same as going from Aniums>Novus. Another reason to be able to farm alexandrite from FATEs and not just for redistribution of points.