The gameplay loop revolves around popping Tempo to get your stacks quickly and using those stacks to burst people down with War. One full combo of War with this talent is enough to kill a squishy. For this reason, duration on Piercing Momentum is more important than Sharp to increase the effectiveness of the talent, and I actually don't recommend using duration on Sharp stacks at all.

The only necessary cards are Casual Competency 5, In The Thick of It, and He Shot First. Other than that, you can fill the deck however you want. I like to use Swift Strikes and Deadly Flourish because base Deadly Momentum kinda sucks.

Casual Competency is for the stacks, definitely need this one at level 4 or 5. In The Thick of It gives you enough ammo for one War combo per level, so you can run it at whatever level you want but I think level 2 is more than enough. He Shot First for more uptime on Casual Competency, you can never have too much of this card in my opinion, but I usually stick with level 3. I don't recommend using The Finer Things with this talent because you'll want to be mostly using War anyway, and you'll want to buy Nimble first anyway so it's kinda obsolete

Nimble is by far the most important item, and should usually be rushed to level 3. After this, it really depends on the match. Resilience and Kill to Heal are always good, but I also think Chronos is a decent choice if you have the extra credits. It lets you throw stuns out way more often, and therefore get stacks more often. That being said, most other items are still going to be better.