Warframe Catabolyst build guide: Critical Mutation, reload mechanics, and more

Warframe's Nightwave Volume 5 introduced a new Catabolyst augment mod called Critical Mutation. While this mod gives the Catabolyst a much higher power ceiling, this is offset by myriad bugs and design issues. In its current state, Catabolyst is the poster boy of gimmick weapons in Warframe. Nevertheless, you may want to give it a whirl if you like red crits with ridiculously high damage numbers.

The "gimmick" Catabolyst leans on for these high burst damage numbers lies in its reload. Like Tediore weapons from the Borderlands games, Catabolyst's discarded empty clips become grenades, causing an explosion during its reload animation. Even outside these trick gun shenanigans, Catabolyst still has its uses as a semi-decent beam weapon.

Best Warframe Catabolyst mod build with Critical Mutation

Warframe Catabolyst mod build with Galvanized Shot to benefit from extra status procs (Image via Digital Extremes)

The blueprint for Catabolyst can be purchased from the Bio Lab in your Clan Dojo. You need Deimos-exclusive resources, including Scintillants, to craft it. As discussed earlier, Catabolyst works as any other beam secondary, such as Kuva Nukor.

The explosion stats are distinct from those of the main weapon. Moreover, it deals significantly more damage upon a full reload from an empty clip compared to a partial reload.

Grenade throw stat	Partial Reload	Reload from Empty
Damage	203	1997
Critical Chance	11%	31%
Critical Damage	2.9x	2.9x
Explosion Radius	5.0 m	7.0 m
Status Chance	43%	59%

Thanks to the much higher base damage and critical chance, it's easy to see how even additive critical chance can help the grenade mechanic hit critical mass, potentially dealing millions in damage.

The Critical Mutation mod grants a 30% critical chance and critical damage buff per kill, stacking up to 300%. The catch is that you must land the grenade throw on at least three enemies, failing which one stack will be deducted from the bonus, shoehorning this build into using the throw correctly.

The above build, however, is a hybrid that utilizes the regular beam as a primer with Viral damage, while the grenade explosion is the main source of burst damage.

How to get the Critical Mutation mod

Critical Mutation is available as a rank 13 reward from Nightwave Nora's Mix Volume 5. However, if you missed it during this window, the mod is still tradable between players.

Riven mod recommendations

You can use Warframe.market to look for Catabolyst Rivens (Image via Warframe.market)

Catabolyst has a serviceable riven disposition at 1.20x (Update 34.0.8), so you can make it perform much better with an optimal riven roll. A good riven mod for Catabolyst should include at least two of the following:

Negative Magazine Size
Critical Chance
Critical Damage
Fire Rate
Damage
Cold/Toxin

You can take out either Galvanized Diffusion or the faction damage multiplier mod to use a Riven mod on this build.

Catabolyst bugs in Warframe Update 34

Several Catabolyst-related bugs and potentially unintended interactions exist at the time of writing this article (Update 34.0.8).

Catabolyst originally had some innate punch through, which is inexplicably gone now.
Due to its explosive properties on the grenade, even modding extra punch-through will not give you punch-through in practice when using the beam.
The grenade explosion does not benefit from Multishot.
The grenade explosion radius does not increase with Fulmination or its Primed variant.
The Synth Charge mod unintentionally benefits the grenade damage.

For the above reasons, Catabolyst has weak application purely as a beam weapon. Not only can you pierce enemies to affect multiple targets, but modding for the grenade also forces you to leave out Multishot, which is crucial for any beam weapon.

Reload-cancelling with Catabolyst in Warframe

You can use the Warframe's Synth mod holster auto-reload passive to abuse reload canceling (Image via Digital Extremes)

Note that reload-canceling on an empty clip won't give you the bonuses of a full reload on the second throw onward. However, you can use the following strategy (functional at the time of writing) to bypass this:

Use a polearm as your melee and any one Synth mod anywhere on your loadout.
Reload Catabolyst from an empty clip and immediately quick melee before the reload finishes.
Once you switch back to the Catabolyst, the clip will have a low amount of ammo loaded due to the holster reload (3 rounds for default magazine size).
Emptying these few rounds again gives you a full 'reload from empty' bonus on the next grenade.

Additionally, there is an unexplained mechanic with the grenade throw that you need to be aware of. As a quality-of-life feature, the weapon does not auto-reload on an empty, so you can manually reload it and target the grenade.

However, an untold timer equal to your reload time (1.7s) also starts after the clip empties. If you exceed this timer before manually reloading, your grenade will only get the stats of a partial reload, greatly nerfing your damage.