Mondrak, Glory Dominus doubles tokens that would be created under your control. That applies to creature tokens and to resources such as Treasure, Food, and Clues, making it useful in white token decks and artifact engines alike. Its four-power body also contributes to combat while the doubling effect improves the rest of the board.
Smothering Tithe can create two Treasures from each successful token-producing trigger with Mondrak in play. Avenger of Zendikar can create twice as many Plants, giving later landfall triggers a larger army to improve. Anointed Procession or Parallel Lives can multiply the result again, so two doubling effects normally turn one proposed token into four.
Mondrak can place an indestructible counter on itself by paying its activation cost and sacrificing two other artifacts and/or creatures. Spare Treasures or expendable creature tokens can pay that sacrifice requirement. The Phyrexian white symbols allow some of the mana payment to be replaced with life, making the protection available in situations where white mana is limited.
The two sacrificed permanents are paid as a cost, so they are already gone if an opponent responds by removing Mondrak before the counter arrives. Indestructible also does not prevent exile, sacrifice, or toughness reduction. Mondrak creates no tokens by itself, and a large creature board can still be vulnerable to a broad reset. Include enough reliable token producers to use the doubling effect quickly, then choose whether preserving Mondrak or spending those tokens on another payoff is more valuable for the current position.
