1. Mulligan for the following cards:

2. Use secrets, Petting Zoos, and Lesser Emerald Spellstones to survive the early game.

3. Play Feugen or Stalagg, have one of them die, and then play the other and start activating its deathrattle with cards like Play Dead and Feign Death.

4. After both Feugen and Stalagg have died start resurrecting copies using cards like Jewel of N'Zoth and N'Zoth, the Corruptor and triggering their deathrattles.

5. Overwhelm the opponent with board upon board of Thaddius.

Have fun and summon as many Thaddius as possible, let me know how many you have at the board at once.