Hirudo

The Hirudo are Infested sparring weapons based on the Kogake, which can steal health from enemies on critical hits.

Characteristics
Advantages:
 * Highest base damage of all sparring weapons.
 * High damage – making it effective against Armor.
 * Tied for highest critical damage multiplier for melee weapons with Dual Cleavers (Prisma), Dual Ichor, Dual Raza, Atterax, and Dual Zoren.
 * Innate 5% lifesteal on critical hits.
 * Adds 5% health buff based on rank 0 of Warframe's base health to max health for 15 seconds after successful critical hits, up to 25% or 5 stacks. Critical hits also replenish buff duration.
 * Decent attack speed.
 * Comes with an innate polarity.
 * Stance slot comes with a polarity, matching Brutal Tide.

Disadvantages:
 * Low and  damage – less effective against shields and health.
 * Short range.

Tips

 * Since it only requires Critical Hit to activate both abilities and it doesn't require to switch to melee and energy, mod with True Steel, Blood Rush or Maiming Strike to increase Critical Chance and any damage mods to increase lifesteal.
 * Berserker is useful in heightening one's attack speed in order to initiate more critical hits.
 * A fully ranked Blood Rush along with increased melee attack speed will easily allow one to heal faster than most enemies can deal damage.
 * Using a warframe with higher armor values can help one stay alive while finding a target for the Hirudo's life steal.
 * Using this weapon with either stance equipped as Inaros can make charge attacks quite effective, as landing a charge attack on an enemy who remains alive after it connects will instantly transition into a finisher, which will activate Inaros' passive to gain health on finishers.

Trivia

 * Hirudo is a Latin word meaning "leech".
 * Its name may also be derived from the Japanese words Hiru (蛭), which means "leech", and Do (道 read separately as Michi) meaning road or way, referring to a way of life or teaching e.g. Judo, Kendo.