Question about +stat buffs on familiars

I picked up a Chief Qualm Guardian (lvl 157) familiar. The description states "a large amount" of w.def for the party- it actually gave a whole +50 w.def. It also has a 80% KB while attacking- in fact it overrides my attack sometimes and KBs enemies into me (if they spawn between me and the familiar). Do these rank up or what are the different circles on the bottom of the card mean?