Check the mod priority guide:
https://docs.google.com/spreadsheets/d/1ty239kyJbBs1sLhTo1JvSWuN0mIJsK1nwVdI6OLLtXo/view?rm=minimal100 Shiki, after so long, can finally make a true name for herself outside of the JP server with her new fancy Neural Upgrade. The core ideas behind 100 Shiki remain the same: If her HP Shield breaks, she will receive defensive buffs, if her HP Shield expires, she will receive offensive buffs. An interesting idea for a hybrid SMG but one that never really paid off.
Now, she has much more substantial defensive benefits when her shield breaks thanks to her Skill 2,
Sakura Blizzard, which prevents the first instance of damage that would kill one of her links and grants an HP shield which gets stronger as her HP drops. Combined with a much reduced ICD and Cooldown on Skill 2, this greatly enhances her defensive capabilities to become slightly stronger than that of RO635 MOD (without setup).
100 Shiki’s main downside is not even one really with herself, but more with her competition. Suomi MOD boasts incredible survivability that far exceeds 100 Shiki at the exact same cost in terms of resources. Nevertheless, 100 Shiki MOD is strong on her own merits and worthy of consideration.
MOD2 is where she gets the bulk of her new power from, with MOD3 being an optional upgrade thanks to her nice but ultimately unneeded Special Equipment.