The idea of this build is fix the problem with Vesper: mobility.
For early game, getting Spiral + Wealth early can easily help you print money if equipped to the same memory.
UMBRAL EDGE: Best for single target buff.
ARROW STORM: Helps spread your on-hit attacks to multiple targets. Glacial Core + Frost together is good for extra dmg + HP stacking (potentially avoid getting one shot). You can honestly run essence you want for this.
HYSTERIA: Can make use of the 2 memories to just wreck havoc. Guidance + Clemency will allow you get massive shield to prevent getting one shot.
BLINK: The dash he needs to dodge the big circles in Hunter V stages since his default dodge collides with enemies. Spiral is to help proc Quicksilver so you can keep run and dodge boss attacks without needing to use Blink.