Xefreni, Travelling Mercenary

First strike, vigilance
During each upkeep, if Xefreni, Travelling
Mercenary dealt combat damage to a creature
last turn, it gains +1/+0.
If Xefreni, Travelling Mercenary has power 5 or
greater, it loses first strike and gains double strike.
"I will fight your battle, and walk away as
your champion."