star guardian chibi lux

hello everyone, sorry if this is a dumb question but i'd really appreciate some help. i recently bought the chibi lux thinking i could use star essence to upgrade it to star guardian lux as i rly rly rly rly want the tactician. i soon realized after spending 1900 rp that that option actually isn't available? can someone tell me how to get it or is it simply not possible anymore?? i don't even like the base chibi lux that much and it's not even refundable...

edit: does anyone hav the star guardian lux & if so how many rolls did you do?