Nexus

At the beginning of the game and each time this card is destroyed, put it into exile.
You may cast it from exile.
{3},{t}: Search your Library or Graveyard for a Probe and place it onto the battlefield with 1 Resource counter on it, then shuffle.
{t}, Remove X Resource Counters from Nexus: You may Cast a Creature Card with Converted Mana Cost of X or less without paying its mana cost. (Activate only as a Sorcery, and only Once each turn.)