Solution

The End Of Enigmatics

1. https://kukkelis.tumblr.com/death
Check out this cord = check discord. 011621 represents January 16th 2021. The source code has a comment saying "Cow level" which is a reference to the author of this riddle. Use the search function in enigmatics discord to find messages during that date from the author. There's only a single message saying "I am the sun, I rise above the world". The page title is asking "what am I" so the answer is: "sun".

I was made aware that not everyone participating in this weekly season is in the enigmatics server, so I was kind and planted a similar message to get the answer in the Notpron server. If you refuse to use join either idk what to tell you.

2. https://kukkelis.tumblr.com/sun
Here you are presented with the numbers 2 20 7 7 3 and some Greek letters. Helios is also a reference to Greece. Go to dcode or manually get the corresponding Greek letters based on the numbers. 2=beta 20=upsilon 7=eta 7=eta 3=gamma. Here you have to take some artistic liberty and think of the Greek letters as pseudo-Latin letters. The answer is "bunny".

3. https://kukkelis.tumblr.com/bunny
You are given the cipher text "tzbtkhu" and the symbols for phi and shift. The golden phi and the title "downward spiral" hint towards the golden ratio, which is roughly 1.618033. Using the shift cipher where t=1 z=6 b=1 t=8 k=0 h=3 u=3 you get the answer "stalker".

4. https://kukkelis.tumblr.com/stalker
The page title means blood written in kanji. The numbers and units are specific ideal reference ranges for different blood tests. Googling them gives you:
b-leuk = 3,4-8,2 e9/L
p-alat = <50 U/L
e-mcv = 82/98 fl
b-eryt = 4,3-5,7 E12/L
p-na = 137-144 mmol/L
p-tni = <45 ng/l
Taking the first letter of each of these substances gives you "lament".

5. https://kukkelis.tumblr.com/lament
The final level contains the numbers 10 7 9 11 12 15 5. There are various hints to lead you to the right direction to make use of those numbers. The title of the page is angel written in kanji. The image says "rebirth and the url of the first page is "death", death and rebirth is a title for a Neon Genesis Evangelion movie. The End Of Enigmatics is also a reference to an Evangelion movie. The page titles written in kanji are supposed to make you think of Japan. The source code has a comment saying "1 is Adam". With all this information you are supposed to find a list of angels in Neon Genesis Evangelion.
10= Sahaquiel
7=  Israfel
9=  Matarael
11= Ireul
12= Leliel
15= Arael
5=  Ramiel
Once again taking the first letter of each name gives you the word "similar".

6. https://kukkelis.tumblr.com/similar
On this page you are given the final solution which is "Longinus".