There are a ton of ways to pump Narset's power and toughness up as well as create favorable attacking situations - Pump spells (on top of prowess triggers), equipment, auras, and anthems all work well
A lot of the Tyranids in this deck have X in their casting cost and come with a new keyword ability called ravenous. Ravenous has the same text as you see on tons of hydra creatures, saying that they enter the battlefield with X +1/+1 counters on them
If the world wants to talk about the green instant that cost You can even forget about the name
Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win. This quote sums up why you should focus on your opponents and only engage when you have accumulated maximum knowledge about the battlefield
Invasion of InnistradInvasion of Innistrad Hm, a bit of a grim note here
A legendary sorcery can only be cast if you control a legendary creature or planeswalker