Battleforged Knight

At the beginning of your upkeep, put two +1/+1 counters on Battleforged Knight.
Remove a +1/+1 counter from Battleforged Knight: Battleforged Knight gains first strike and vigilance until end of turn. Activate this ability only on your turn and only once each turn.
At the beginning of your end step, if Battleforged Knight's toughness is 5 or greater, shuffle it into its owner's library.