Hi there, 

I play Raid for 11 months with several accounts, combined from all accounts I have all champions / except Baron/. Yes, I`m whale. 

This post will be mostly for Clan Boss, Poison is NOT a damage and three champions and no working masteryies. 

Clan Boss 

*All the numbers are from Easy Clan Boss / reason is that everyone can check it even the lazy moderators, also the numbers are higher/ 

25% is way more than 60% 

Yes, with 25% weaken debuff you will do way more damage then with 60% defence down with warmaster or giant slayer procs. 

Without 25% weaken and without 60% def down - one proc is 63 653 damage. 

With only 60% def down one proc is 70 193 damage 

With only 25% weaken one proc is 79 567 

With 25% weaken and 60% def down one proc is 87 741

So if you do not have champion with def down - do not worry is only 9 374  less compare to 25% weaken - better put one more 5% poison its 20 000 - almost 11 000 more damage than 60% def down!!!

If you have 25% weaken + 60% def down you will get 8 174 "more damage" compare to have only 25% weaken, but this is a lie - see one 5% poison tick is 20 000 damage in the same place for this 60% def down, so actually you lose almost 12 000 damage per boss  turn.

Now, many of others will say - "Speed is the key, I`m 2 or 3 times faster than the boss so I will hit it more often and i actually will do more damage with both weaken and def down." Try, but only for easy, normal and brutal boss. As I wrote above, all the numbers are from easy Clan boss - bigger numbers, the change of difficulty of the boos is changing the numbers - they get lower, but the gap between def down and weaken is growing and the speed is not so important. 
Because we do not have the REAL stats of the clan boss, I personally suggest the new and the mid range players do not bother with def down.

Poison is NOT a damage 

yes, according to Plarium logic/again/ poison is not a damage! "Are a crazy I see it as damage in my final count of damage dealt in a clan boss!" Yes, I also see it as damage, but do you see even a single time your poison to heal you / if you are with life steal set/? I never see this. Poison is not a damage over time in this game, here is damage per turn, this is not so important in my opinion, but maybe that's why we all can NOT heal from our poisons on a clan boss - imagine to heal your self for 30% of 5+ 5% poisons this will be a dream for all the players, it will lift survivability so high.... but Plarium somehow ignore this poison damage and it count as no damage to heal us.

Warmaster and Giant Slayer are NOT count as damage 

I use BEK and Lugan for Clan boss. / down I will write more about them/.  

BEK: 

Dark Sphere 

Attacks all enemies. Heals this Champion and all allies by 20% of the damage inflicted. 

Lugan: 

Crushing Blow  

Attacks 1 enemy. Heals all allies by 10% of the damage inflicted. Places a [Shield] buff on this Champion for 2 turns equal equal to 10% of their MAX HP.

Both skills MUST HEAL ALL allies for % of the DAMAGE inflicted. They are not healing. When I proc Warmaster with them...... nothing happen, they do NOT heal allies! Again Warmaster proc is not a damage? Fix? Maybe soon?

Champions. 

Bad El Kazar 

Why is so hard to write one word more for his passive?! What I mean is that NOW his passive is for ALL champions in the party, not only him! Change the description of his passive or change the passive as its writes! Fix Maybe soon?

Lugan /my favorite champion / 

Above I mention his A1 is not heal allies with warmaster proc, also mastery Selfless Defender is not working with his A1. In campaigns when he hits someone with A1, he gets a shield, enemy is hitting some other party member and Lugan recieved 20% damage directly in his HP / red damage/ the shield stays not touch.

Valkyrie  

Stand Firm  

Attacks all enemies. Places a [Shield] buff on all allies for 3 turns and a [Counterattack] buff on all allies for 2 turns. The value of [Shield] and the damage inflicted are proportional to this Champion’s DEF.  

Question: how much exactly is this proportional? This is broken as F**K. Why its so hard to write 4,5,6 times the champion DEF?

Athel

The mastery Heart of Glory: +5% damage when attacking with full health. Not working properly with Atel. 

Case: Atel has a poison from clan boss, she get turn damage is received - she attacks with A, 1 hit heal her to full and the last two hits MUST do more damage than the first one according to the Heart of Glory mastery - NOPE!

Soon I will write part two of this post, hope some hot fixes to come before Christmas this year / 2019/