Li, Deity of Mt. Xuan Hu

{2}{b}, Sacrifice a creature: This creature gains
renown 1 until it is put into the graveyard or
exiled. (Whenever this creature deals combat damage
to a player, if this creature is not renowned, put a
+1/+1 counter on it and it becomes renowned.)
When this creature becomes renowned, you may
search your library for a central ancient card,
reveal it, put it into your hand, then shuffle your library.