High damage, excellent Gatlings, a good juggle, and it's bloodless. Don't use more than 2 in a combo or risk dropping the combo due to the same attack juggle penalty. Multiple c.S juggles are your baseline filler in the corner when trying to fill out a combo before you've built enough wall damage for a 6H Wall Splat.
Similar to close slash, with slightly worse damage and Gatlings. Importantly gatlings into 6H which is your preferred Wall Splat. Often used interchangably with c.S in corner juggles, but its very slightly higher juggle occasionally means you'll prefer 5K to c.S to avoid drops on tight links. Has the benefit of not being a proximity normal, so it sometimes allows pickups in post-236K situations where pressing S will give youf.S. This is Nago's only jump cancellable normal but this functionality sees very little use outside of niche j.K>j.D wallbounce routes. When juggling in the corner, put a slight delay between your 5Ks while holding back to OS enemies attempting to burst on the 5K hitstop.
c.S > 623H > 236K:
Suboptimal extender that nonetheless works in virtually every situation. Juggles high enough to almost always connect into a subsequent c.S pickup. Keep the blood cost in mind - you can only do so many of these in a combo, particularly without offsetting blood draining normals. It's very flexible but the poor blood profile means that better filler is often available. Since it works even on heavily prorated combos, can be helpful to use after Red Roman Cancel when you aren't sure how to continue.
(c.S) > 5[D], (c.S/5K/2K):
Very high damage bloodless filler which is only possible in the corner on high juggles off of good starters/roman cancels. Due to the high blowback of 5[D] and certain characters' hitboxes in juggles, you may need to pick back up with 2K before splatting with 6H
c.S > 2H > 236S > 236k > (c.S/5K):
A reasonable choice of filler in or near the corner which offers a solid amount of damage for reasonable blood management due to 2H's blood drain offsetting 236S's blood cost. A good choice on more damaging starters like CH 214H. Downsides are that it is reliant on distance to corner - you have to route consciously around stage position using this string.
c.S > 2H > 236k > 623H > 236k > (c.S/5K):
More expensive than c.S > 2H > 236S > 236k due to the extra fukyo, but not dependent on position to corner. Pretty tricky to execute compared to the standard 623H extensions.. 623HGuard:
-7 juggles slightly higher with lower forward momentum than 236SGuard:
+5 does, so route accordingly.
c.S > 5H > 623H > 236k > (c.S/5K):
Your best option in the corner for filler. Only possible very early in certain high-juggling combos. The same blood profile as c.S > 2H > 623H > 236k > (c.S/5K) but for more damage and less wall damage.
623HH > 214H > 623H:
For when you want to make sure either you or your opponent dies in one combo. Very flashy and high damage but incredibly weak to enemy burst given the very high blood cost. Only possible on higher juggles - 623HH won't ground bounce high enough for 214H to pickup on prorated routes. This is absolutely not a recommended string for beginners. The most common situation on these routes is a blood pop, and most routes involving this string are trying to either intentionally combo into that blood pop or land a kara Super (632146K~S or 632146H~S) and kill their opponent before that happens.