Nanaya summon is only useful for zoning, and its pretty crappy at that. It hits fullscreen tho, so when you want to harass the other side or bait them to coming to your side, Nanaya summon shines in that regard. If they try to jump it, you could try dash-in 623c but that's just gimmicks. Nanaya summon, like most of Warachia's normals, is generally just a poke and something you throw out to fill up the screen. Don't use it unless the other person is on the opposite corner or after a blockstring ender (preferably 5c) because it has some pretty terrible recovery. Nanaya summon after throw works as a meaty but its pretty risky since you'll probably lose to reversal DP.
Nero summon is only useful after knockdown and, as far as oki options go, isn't that bad. Midscreen it generally loses to reversal backdash although you can bait that with 2c, 5c, or dash 5b. In corner, its absolutely wicked as you can delay it for throw. It also creates a safe Force Heat setup since the Nero claw covers. Nero summon major setbacks is that it loses a lot to shield, which shuts down the 2a, 2b, IAD j.b options. It also loses out to jumping of all things, which means you should go for the 2a or 2c meaty to get respect. One of my major peeves with Nero is that it does not hit the opponent out of reversal DP. So if you dash in and eat EX DP from Nanaya, Nero generally will not Nanaya out.
I think the most underrated setup that not a lot of Wara's use is EX Tornado. It pretty much splits the screen at the divide and has a ton of frame advantage on block. Best of all, you can use it as a meaty after EX Pinwheel and its safe. I generally use EX Tornado after 5c 22 to stuff anyone from dashing in or after throw/EX Pinwheel if I want a safe Heat setup. It only loses out against Ciel but that was pretty much a given. You can't combo after it unlike Warc summon, but at 50% cheaper, it's more user friendly. Use EX Tornado at range and optimally at half screen. If they auto-shield the tornado, go for the throw or the jump-in.
