Chapter 1: POWER SYSTEM
It is for those who don't know about the TOWER OF GOD power system. The population of the tower far exceeds the population of the earth and is several times the earth in surface area.
First, the highest possible floor possible as of yet is 134th
REGULARS RANKING
A-rank Regulars
Possibly the highest rank a regular can obtain, above B-rank regulars.
B-rank Regulars
Are Regulars that have transcended the strongest of the strong individuals of D and C-rank Regulars.
C-rank Regulars
Are all Regulars who have passed the C-Rank Regular Test, which happens somewhere between the 49th Floor and the 51st floor.
D-rank Regulars
Are all Regulars who passed the 30th Floor.
E-rank Regulars
Are all the Regulars who passed the 20th Floor.
F-rank Regulars
Most Regulars that come into the Tower on the Second Floor.
RANKERS
A Ranker is a being who has reached the top of the Zahard Empire (currently 134th Floor) and has been given a Rank. This Rank should not be confused with the Ranking and Grading that both Rankers and Regulars continuously receive.
If a Ranker's ranking is in the top 10% of total Rankers, they are considered an Advanced Ranker. There are about ten thousand Advanced Rankers (including the top 1%) in total.
If a Ranker's ranking is in the top 1% of total Rankers, he/she is considered a High Ranker. There are about 1000 High Rankers in total. High Rankers are often described as gods among gods.
SHINSU
It can be basically referred as mana system of some other anime it can take any form water, fire, weapon etc. Everyone inside the tower can manipulate shinsu to some extent after they form a contract with the administrator of that floor.
Irregulars are an exception to this rule as they use the shinsu even without the contract.
Irregulars are feared because of their abnormal power and growth whenever one comes they only create chaos.
ENRYU (RED TOWER)-killed the administrator of 43rd floor when they were supposed to be immortal beings.
And now three new irregulars have entered the tower once again what is going to happen....
Weekly Power Status
-- Power
Ranking 
-- Power
stone