mtg playtest card Wowzer, the Aspirational [Mystery Booster 2 Cards] Pre-Alpha Playtest Power 9 :

Thanks to this, Thanos, the Mad Titan looks like one of the best new Commanders when built around

5C mana-fixing rocks like Chromatic Lantern, Fellwar Stone, and Coalition Relic are perfect here, but even the signet cycle (Golgari Signet) and the talisman cycle (Talisman of Creativity) do a great job here

----- Flying Demonic Taskmaster Rarity: Uncommon TYPE: Creature SUBTYPE: Demon CMC: 3 Mana cost: USD: $0.22 EUR: 0.24 TIX: 0.04 EDHREC RANK: 9485 (4/3) Flying At the beginning of your upkeep, sacrifice a creature other than this creature

That's right, this means that a Siege's controller can attack it with their creatures, and the opponent they chose as its protector can assign their own creatures to block those attackers