Saberis, Underworld Keeper

Defender, triple strike, menace, obstruct 2,
resist white and blue ( Prevent all damage from a
white or blue source dealt to this creature.)
If an opponent has 5 or more cards in their graveyard,{1}: Monstrosity 1
If Saberis becomes monstrous it gains vigilance
and can attack as though it didn't have defender.