Check the mod priority guide:
https://docs.google.com/spreadsheets/d/1ty239kyJbBs1sLhTo1JvSWuN0mIJsK1nwVdI6OLLtXo/view?rm=minimalAS Val rises from one of the weakest base ARs to being one of the strongest ARs for night performance assuming you can give her the right support to reach her max potential. This isn’t always needed in the Girls Frontline meta, but it’s nice to have her whenever night battles become relevant.
What makes AS Val MOD strong is
Faith, her Skill 2. Whenever AS Val receives a damage buff from any source (Fairy Skill/Talent, HG buff, or even her own Skill 1), she gains surehit for 3 seconds. When combined with certain support, she can completely forego using a PEQ at night in favour of a VFL.
It should be noted that if you lack the means to give her this Skill 2 coverage, then AS Val does become considerably less worthwhile against unarmoured enemies due to a lack of continuous Faith activation, forcing her to wear a PEQ.
AS Val MOD also enjoys a nice stat boost, an upgraded Skill 1, tiles that finally face forward , on top of a good Special Equipment that bumps her raw damage up further. Everything combines to give her some of the highest DPS at night for ARs.
Unfortunately for AS Val, even when night maps come up and you happen to need an AR, plenty of other ARs can perform perfectly well without needing to go through the upgrade. If you do upgrade her, getting her to MOD2 for the skill is the minimum, but getting her to
MOD3 allows her to enjoy her great Special Equipment.