You should 100% be using Sepulcher.
Sepulcher is your best Attack Down champion.
You probably should use her in your Clan Boss team.
I don't see Rhazin in your roster.
It seems like you haven't fused him from Portal, yet.
The only Def Down + Weaken hero I see in your Roster is the Dwarf.
Rugnor Goldgleam seems to be the only option you have.
You probably should use him in your Clan Boss team.
1 - Sepulcher (Atk Down + Increase Defense + Block Debuff Buff)
2 - Rugnor Goldgleam (Def Down + Weaken + Leech)
3 - Frozen Bahsee (Poison + Poison Sen.)
4 - Skullcrusher (Counter Attack)
5 - Flex Spot
The hero I would pick for 5th spot would probably be Zelotah.
Zelotah does Shields and I think Zelotah looks cool.
In Addition, Lets say you decide to remove Zelotah from your Clan Boss team 1 day.
Zelotah is insanely good for Faction Wars
Here is a Screenshot of my Zelotah helping me defeat Stage 21 of Undead Faction.
Zelotah is insanely good for Dungeons
Here is a Screenshot of my Zelotah helping me farm Stage 20 of Ice Golem.
Zelotah is amazing in Doom Tower vs. Scarab King.
Here is a Screenshot of my Zelotah helping me defeat Floor 50 on first rotation of Scarab King.
Honestly, if you look at the reviews on Zelotah, You can further see how crazy he really is.
4.8 to 5 star reviews on this hero for almost everything.
The game has like 15 or so different game areas.
Zelotah scores 4.8 to 5 star in all of them except 2 (Spider + Fire Knight).
I fully booked my Zelotah.
I fully mastered my Zelotah.
I have no regrets.
Great! I think I need to start farming for good level Lifesteal gear so I dont need to use Scyl and apothecary.
I think the best reward Brutal mode can give is Void Shard or Epic Tome.
To get Sacared Shards & Legendary Tomes, you need to attack NM or UNM.
This is why a lot of players strive to reach NM or UNM Mode.
It allows them to get better rewards.
Since, you are 2 keying Brutal Mode.
You could give NM Mode a try.
You might be able to 3-4 key NM Mode.
Worse Case Scenerio, You fail to reach Max Chest on NM Mode.
It will at least give you insight on what you may need to improve.