I've been getting pretty unlucky with my pulls so far, especially for colourless. My core team consists of 5* Tharja, 5* Peri and 4* Fae, so I am actually consindering investing some time to train up and promote my 3* Serra to 4*. I think she is seen as a pretty mediocre healer but her amazing buffing potential might come in handy for a Tharja-centric team? (My queen Tharja got a really good +Atk, -Res nature too <3)