The remotely triggered Castanas quietly deliver a lethal dose of electricity to unsuspecting enemies.
The Castanas are a throwing type secondary weapons with an electrical detonation charge that can be detonated remotely by using the zoom command, much like the Penta. Although lacking in throwing speed like other thrown weapons, they can be stacked up to 6 then detonated all at once to create a wide array of crowd controlling opportunities thanks to their electrical explosion and chaining effects.
100% chance to proc Electricity regardless of installed mods, have 10% base chance to additionally proc modded damage type.
Electricity proc provides very high stun chance against most humanoid enemies.
Electricity proc chains damage to enemies around it, making this weapon great against crowds.
Silent, even if the projectile hits the enemy.
User can detonate charges on command, giving the player precise timing in detonation.
Up to 6 charges can be ready for detonation at the same time.
Two Polarities.
Has base damage type of Electricity, allowing Castanas to easily be modified to Radiation damage for Heavy Grineer units, Corrosive damage for Ancient Infested units and Magnetic damage for Corpus units.
Disadvantages
Deals Electricity damage, which improves its utility against Robotic or Machinery-type foes but not others unless properly modded.
When Magnum Force is added, the Castanas will begin to spread apart on throws if Multishot mods are applied. This may be helpful for combating the small blast radius they have by spacing them slightly apart from each other.
Throwing these at an Arctic Eximus snowglobe and detonating them will kill the Eximus.
Castanas uses the pistol ammo mutation mod not sniper ammo mutation, while still using sniper ammo.
Castanas thrown by Mirage's illusions from Hall of Mirrors will not interfere with the maximum amount of armed Castanas at a given time.
Tips
Caution should be taken when this weapon possesses elemental damages such as Magnetic, Toxin and Viral, as these would deliver their corresponding negative effects should the user be caught in the blast area.
As a Nyx, throwing several Castanas to the floor, casting Absorb on top of them and detonating them makes a good (and fast) combo for an instant "charging" Absorb with the right build.
Mirage'sHall of Mirrors can be used to increase number of Castanas that can be planted, but the holograms' Castanas will detonate a few seconds after impact; though they will not damage the player and can still also be detonated manually.
If you are willing to take the damage, you can detonate the Castanas right on top of yourself by pressing the fire and zoom keys at the same time. This technique is useful for Link + Blessing Combo.
Note that as of Update 13.3, the Link+Blessing Combo is less effective, due to the fact that Blessing doesn't confer invulnerability any longer.
Trivia
The Castanas are the first thrown secondary weapon that delivers Area of Effect damage.
The detonation feature is similar to that of the Penta grenade launcher, which also allowed users to detonate on command in exchange for zoom.
This makes the Castanas the first secondary to have its Zoom feature replaced with a different function.
The word Castañas means "chestnuts" in Spanish, judging how the knives are thrown, then "open" themselves, revealing their explosive cores.
The Castanas are the first throwable weapon of its kind to be thrown in "Semi-auto".
Bugs
Although the Castanas use Sniper Ammo, they are a secondary weapon, which disallows the use of the Sniper Ammo Mutation mod and instead uses the Pistol Ammo Mutation mod, which strangely still functions properly.
Due to the Castanas' nature of using sniper ammo since their ammo capacity was fixed, they will alter the ammo capacity of primary weapons that utilize sniper ammo.
Equipping the Castanas with any sniper or bow weapon will decrease their overall ammo capacity.
Equipping the Castanas with the Ogris, Torid, or Penta will increase their overall ammo capacity.