>>533898291
sounds plausable, tho imo after getting all the good lines it's better to move onto other nikkes than trying to minmax to get all black lines.

>>533898494
>roll till you get a desired attribute on line 3 (ele, attack, ammo, charge etc.)
>lock line 3
>roll till you get a desired attribute on line 2 (ele, attack, ammo, charge etc.)
>lock line 2
>roll till you get a desired attribute on line 1 (ele, attack, ammo, charge etc.)
>look

For further minmaxing consult the graph. Basically you want all lines to be at least at lvl 9. Getting lvl 7-9 lines + few lucky blue / black is the most any reasonable person should minmax OL gear