First world problem

So, i got the Xmas rifle (from a previous aero event). Now at this aero event I was aiming for Lulu. Now I got lucky a landed on the 12o’clock Random sTier character box and I did get Lizzy (had no other STier char before).

My question: should I get Lulu (I know 10% cp) OR should I start collecting Xmas rifle accessories (now that ascension is available)?
I tend to getting LuLu but what is the most efficient way to obtain accessories?

Thanks!