I'm deeply sorry for the formating.
I'll only talk about Mythical Weapons. There are differences between Rare, Legendary and Mythical Gear which would make this thread much more complicated but I'll try to explain those for each section below. Also thanks to Seraphinush for a lot of the translation!
Weapon has three different main stats:
1.) Unique Passive Option (Source Seraphinush)
| Weapon |
Magical Rainstorm |
Increase MP cost by 2 times, increase skill damage and effect of healing skills by (4/5/6/7/8)% |
| '’ |
Vicious Curse |
(10/20/30/40/50)% chance to apply effect to decrease Physical and Magical Resistance to target upon successful hit, stacks up to 100 times |
| '’ |
Spiritual Supremacy |
Decrease cooldown of passives with ‘increase Crit Power’ effect by (7/9/11/13/15) seconds |
| '’ |
Determined Strike |
Decrease attack speed by 10%, increase skill damage and effect of healing skills by (4/5/6/7/8)% |
| '’ |
Blood Predator |
Recover (0.01/0.015/0.02/0.025/0.03)% of damage dealt as HP |
| '’ |
Enrage Subjugation |
Increase damage to enraged monsters by (8/10/12/14/16)% |
| '’ |
Mark of Extinction |
(20/40/60/80/100)% chance to apply Mark of Extinction (pl.) to target upon successful hit; deals 0.1% of target’s max HP or up to 10,000,000 damage when stacked up to its maximum of 15 times |
| '’ |
Pledge of Blood |
Decrease healing received by (10/20/30/40/50)%, increase skill damage and effect of healing skills by (2/4/6/8/10)% |
| '’ |
Song of Courage |
Increase Magical and Physical Amplification of self and nearby allies by (2/2.5/3/3.5/4)% |
Explanation: As you can see there are 9 different options who each have five "strength tiers" (in roman numerals 
) essentially meaning that I = weakest II = weak III = middle IV = strong V = strongest option.
On rare weapons you can only get I or II or III ; on Legendary Weapons you can only get II & III & IV while on Mythical Weapons you can only get III & IV & V so for this example we will only look at middle, strong, strongest options because you can not roll the weakest & weak option on mythical weapons.
This leaves us with 9 passive options who each have three tiers left = 27 different options when you receive a weapon.
2.) Two Overline Stats - just like for the Unique passive you can only roll III & IV & V stats on these two options. (These are the same rng stats as the current gear and you will have different stats again - white + green + blue + yellow + purple indicating how strong/high the stat itself is - example:
Crit Factor will be white = 7 ; green = 9 ; blue = 11 ; yellow = 13 ; purple = 15)
So on Mythical gear you're only able to roll the blue + yellow + purple stat and the available options for the weapon are the follwing:
| Physical Amplification |
Magical Amplification |
| Physical Pierce |
Magical Pierce |
| Physical Crit Power |
Magical Crit Power |
Ignore Physical Resistance
|
Ignore Magical Resistance |
| Critical Factor |
----------------------- |
These nine stats are possible to roll on your new mythical weapon and as explained you're only able to get the blue, yellow, purple rarity on the stats - which will result in once again 27 different options to receive (twice of course since you have two rolls available)
3.) Underline Stats are pretty much the same as 2.) but the numbers each stat are a bit lower meaning that the Crit Factor stat is the following:
White = 3 Crit
Green = 4 Crit
Blue = 5 Crit
Yellow = 6 Crit
Purple = 7 Crit
But for these three underline stats sadly even with a mythical weapon you are able to roll ALL five tiers of each stat, meaning that you can get White, Green, Blue, Yellow, Purple no matter what rarity your weapon has. Also compared to the Overline Stats you are now also able to get Physical Resistance + Magical Resistance + HP + MP as stats aswell which increases the amount of possible/available stats by a decent amount. So instead of nine stats (look table above) you now have thirteen different options who each have five tiers now so you have 13 options * 5 stats = 65 different options.
Keep in mind though that you have 3 different underline options so in theory you have 1/65 and 1/65 and 1/65 if you want the best weapon.
Overall tl;dr:
1) Unique passive options = 9 options * 3 tiers = 27 different options
2) Overline stats = 9 options * 3 tiers = 27 different options
2) Overline stats = 9 options * 3 tiers = 27 different options
3) Underline stats = 13 options * 5 tiers = 65 different options
3) Underline stats = 13 options * 5 tiers = 65 different options
3) Underline stats = 13 options * 5 tiers = 65 different options
Meaning that the theoretical best in slot weapon basically has a chance of (1/27) * (1/27) * (1/27) * (1/65) * (1/65) * (1/65) = 0.0000000001849987 or you need roughly (1/0.0000000001849987) = 5.405.443.389 different weapons to on average get one Best in Slot Weapon.
Please if I made any mistakes during those calculation or if I missed anything - feel free to correct me
My opinion: We have been complaining for two years now that the amount of rng stats is too damn high - and you guys really come up with this stuff 
I sincerely hope that not a single player bothers to come back for this joke of a patch and that even more players finally decide to leave this game behind and stop spending money on this garbage casino pay2win shit.
