Check the mod priority guide:
https://docs.google.com/spreadsheets/d/1ty239kyJbBs1sLhTo1JvSWuN0mIJsK1nwVdI6OLLtXo/view?rm=minimalIDW’s American cousin bursts her way onto the Neural Upgrade scene as our first upgradeable SG. Thankfully, M500 got the memo on what a great MOD should be, unlike her British cousin.
Her Skill 2,
Hunting Instinct, will grant herself and other units in her column with a 30 HP shield for 5 seconds whenever she receives a multiplicative stat buff. Note that this shield can stack up to 3 times and also REQUIRES another ally in her column, otherwise the skill does nothing. She synergises perfectly with dolls and fairies that provide constant buffs, such as SAA MOD, whose Skill 2 provides M500 with repeating buffs as long as she’s on the field.
The rest of her neural upgrade is not too important. The most important part is the extra point of Armour she receives, helping more than one might think at first. She also gains a boost to HP. Her tiles now also buff Accuracy and her Armour boost from Skill 1 is higher, though this hardly matters. Skill 2 is the definitive selling point of the package, hence why
MOD2 is her recommended upgrade level. Her Special Equipment is an ITI with some extra crit damage, so it can be safely ignored.
Her SPEQ-set simply improves her performance slightly, but isn't all that amazing. Certainly an option if you have the Memory Fragments to spare, but not required to make her do her job.