Like the deck and love Narset in general. Toying around with a brew of my own. Might I recommend adding more burn instead of the targeted removal like scouring sands and magma spray (adds utility and expands your win con)? And then divination in place of the counter magic since they can't strictly be cast off Narset (exiling dissolve dissolve is gonna be heart-breaking). And then, you get to run Howl of the Horde which gets the raid trigger if cast off Narset. Howl into lightning strike = 9 dmg, or howl into divination = 6 cards. And finally, Maybe add a new Jace into the mix? The +1 adds excellent pre combat card filtering for Narset's trigger, and since there's so much redundancy in the deck you can afford to toss the occasional non walker spell into the yard.

Sorry meant "targeted" and in strictly hits creatures.

*as in

Since you will most likely be using Naraset to cast your walkers for free why not run Garruk, Apex Predator