Savona is one of the two characters who survived the disaster of Fabius' last battle with the Thirteen Scars as described in Josh Renolds last book for Black Library.
To quote the Lexicanum:
'Born to the family to the Imperial Governor on an Agri-World... she began her career in the Legion as one of their Serfs, but that changed when she was gifted with semi-sentient Daemonic battleplate from her master Kasperos Telmar. ... By M34 she was ranked 2nd in the Joybound, the elite guard of Telmar's warband....After The Shattering and Telmar's death, Savona joined Fabius Bile's Consortium warband. ... Following the events on Solemnace Savona was placed in charge of the remainder of the 12th'
Somewhere in the years between the final battle and Time Now, Savona has acquired a new weapon, a boltgun with a built in chain-saw.
The model is from HeresyLab: they make very nicely detailed resin models at reasonable prices - worth a look.