I play the german Steam Version of Warframe and got the sigil bloodshed with the following description: Verursache Schaden, damit dieses Siegel dafür sorgt, dass deine Warframe in Photora getränkt im Blut deiner Feinde steht. Ehre die Jungfrau des Todes, indem du ihr traditonelles Gewand anziehst.
which translate to: Deal damage so that this sigil ensures that your Warframe stands in Photora soaked in the blood of your enemies. Honor the Maid of Death by dressing in her traditional attire.
I read the description in the English Warframe wiki and realized that this seal is completely useless for me.
My Main-Warframe is Ash which most of the time invisible so i get not much damage but i like the idea that the effect of the sigil is shown the more enemies you kill so when visible my warframe is full of blood.
We allready have game mechanicks like the arcane Molt Augmented that counts how many enemies we have killed so it wouldn't be impossible to scale the visibility of the sigil based on how many enemies you have killed.