i currently have a 1 star phantom sword, i understand the second skill need 6 swords for abiltiy to activate but im slightly confused on the first one

if i put it in my thunder grid which has 2 ixion swords at max (lvl 125,skill lvl 20) what will happen basicly?
does it boost its normal stats by some percent or does it do more?

can someone enlighten me on it