I would go for Spirithost Diabolist Warmaiden Skullcrown(Lead).

This is enough to push you to gold. Just need to focus on artifacts. 

Just gear Kael for CB (more defense, hp and acc instead of attack) 

You can later change Spirithost, Diabolist and Warmaiden once you have better champions that do similar job, like Seeker, Gorgorab, Madame Serris, Stag Knight, Arbiter, etc. 

JoinME said:

I would go for Spirithost Diabolist Warmaiden Skullcrown(Lead).

This is enough to push you to gold. Just need to focus on artifacts. 

Just gear Kael for CB (more defense, hp and acc instead of attack) 

You can later change Spirithost, Diabolist and Warmaiden once you have better champions that do similar job, like Seeker, Gorgorab, Madame Serris, Stag Knight, Arbiter, etc. 

LOL.  Good advice, but Gold?  Not anymore lol.  Probably the right comp though in order of speed:

40 Diabolist (speed)

40 Spirithost

50/60 Warmaiden (Accuracy)

60 Skullcrown (NUKE)

@trips haha you don't believe me? Haha I personally did not build Diabolist, but her stats and kit is good. Base speed of 110, fills 15% turnmeter with decrease enemy turnmeter by 15% is almost comparable to 30% turnmeter boost. So Diabolist also needs ACC. 

Spirithost and Warmaiden is just for buffs and debuffs, then Skullcrown nuke is enough. I myself using single champion nuke with Arbiter, Lysandra, Serris and Skullcrown in Gold4 and is nuking almost every team in my list. Can do 100k damage on HP type champion and around 40-60k on defense champions. If without decrease defense, my Skullcrown can still deal up to 50k damage on non defense champion

On Tormin teams, I am still developing this team, Lysandra, Serris, Battlesage, Skullcrown. 

On Siphi Rotos team, I switch Serris with Zargala because I need thos multihits. Although it does not work if enemy has thick shield and high resistance. 

My team is almost similar to Diabolist Spirithost Warmaiden. It is just that I have better turnmeter boost and strip with decrease defense. 

I think arbiter lyssandra serris is a little bit better:)

But tbh, you could probably get to gold with your gear on spirit diabolist and warmaiden. New players are just so far behind. The gear requirements to compete in arena are ridiculously high now. Skullcrown is great to build around. Never got her on either account. 

Ah damn, never thought Kael was leaving the team. So drop some books on Skullcrown as she will be with me for a while while the other ones are supposed to be replaced as soon as I got an replacement?

Thank you so much guys, cleared some things out and realize how I can upgrade the team now. So lets see if I got the theory correct :p

Was lucky as hell yesterday and managed to roll Apothecary. Since skill set is similar to Diabolist, though Diabolist seems to have a bit better turn management, replace her so it is:

• Apothecary (Speed, 1st. Assume lvl 60 as people seem to raving about him)
  
• 40 Spirithost (2nd)
• 50/60 Warmaiden (3rd)
• 60 Skullcrown (4th)

Sorry for spamming this, but helps me check if I am thinking right about the teams and how to upgrade the champs while still keeping similar composition.

Your next 6 star should be Skullcrown.

Skullcrown is far better nuker vs. Kael.

Top Tier - Skullcrown will be your Arena Nuke + Campaign Killer.

She can 1 shot all the waves when you build her right