One of, if not the, best swords in the game and quite underrated by many players.

High base stats and good riv dispo make this an ideal candidate for long Steel Path survivals, especially against grineer given its high slash damage. Tested up to 2 hours on Steel Path kuva survival.

You don't want to add any elemental damage, honestly the slash procs bleed everything in a couple of hits. Adding elemental damage will only make it less likely for slash to proc. You don't need to use a weapon to load up status procs on enemies either.

Having [Gladiator Might] in there not only gives an obvious boost to your crit damage, but the set bonus combined with [Blood Rush] is enough to tip it over the 300% crit chance mark, meaning constant red crits. If you have a riven though, this is the slot it would go in.

As far as rivens go, as with most melee weapons, a groll would be crit damage, attack speed, range with a harmless neg such as crit on slide. Why those stats? Each one gives a direct increase in dps and depending on the dispo, allow you to drop other mods you would normally slot in such as [Primed Reach] and beserker. Having an element on your riven isn't bad, but it will limit the build variation and can knock slash down to second in proc order which you really don't want - unless you're fighting corpus in which case you want a higher toxin stat. Note - heavy attack builds do not follow this rule and while these would still be great stats for a heavy attack build, a groll would be a bit different.

If you go really far to super high levels, obviously you will want to pre-load the enemies with status effects for [Condition Overload]. Most players goto weapon for this is obviously the [Kuva Nukor], particularly a magnetic version as it allows more status types. Something to bear in mind is the [Nukor] obviously deals radiation damage which, as I'm sure you know, make the enemies turn on each other. This can be extremely dangerous to the player as it can be very easy indeed to get hit in the crossfire making death a likely outcome. Try experimenting with other high status aoe weapons and see what else works. I've been using a [Sporelacer] kit gun recently built for status rather than crit and using [Primed Fulmination] to cover a huge area.

You can also obviously use warframe abilities for CO loading. If your chosen frame doesn't have such an ability, have a look at Thermal Sunder, the subsumed ability from Gauss. It's very good for procing, fire/cold/blast.