The whole deck is built to last
Mana Crypt is a two mana boost on the spot, a fine addition to any combination deck, but its drawback is very real
The Twelfth Doctor was a teacher, and to demonstrate that, he works with the Demonstrate ability, letting you copy a spell you cast from anywhere except your hand
The other upside of Inscription of Ruin is that it's also a fine (if slightly overcosted) removal spell against aggro, where killing any creature with mana value three or less hits basically everything against a deck like Mono-Red or Mono-White
Even though it costs seven mana, youll never have to worry about losing your late game play since Tyrranax Rex cannot be countered, letting you cast it without worrying about being blown out on your game-winning play
( Drannith Stinger ) Generating lots of small creature tokens by cycling