Funny you would say this. I beat Epic 5 realitively easily doing exacly that, after struggling for hours with a similar approach to what you shared.
Instead I did Crow, BD, Apo, Keeper, with 3 Medal of Seasons. Block skulls and brown mana while filling your team. Keep blocking and use extra turns to hit Alastair with crow (b/c Armored). When War Shphinx dies, block blue as well to stop Alastair from filling. Then, when Aziris is weak or dead, look for opportunistic free turns with skulls and skull loop.
I’m very glad to hear this worked for you. Based on other responses, I was concerned that I was promoting a strategy that wasn’t actually useful. I cleared level 3 just using skull damage, but it took multiple attempts. Level 4 was not working until I switched to this.
I was trying to use skull damage on level 4 for at least a day with no success, which is why I switched. When I got to level 5, I was able to clear it in 2-3 tries using the strategy I posted. I know there were people in my guild who used skull damage with 3x Medal of Seasons, but for whatever reason I couldn’t get it to work for me, but it’s definitely doable. I’m happy to hear that worked for you.
I wanted to post this method because the direction in the trial description is to use skulls, and I just wanted to share that there was another way for people who were having trouble.
I think either of these methods requires you to be at a fairly high level. It’s definitely an end-game activity. I wish the developers could set expectations that not everyone is going to be able to complete them. I remember when Factions first started, I was at a level where I could not complete many of them. I had to go back later and finish after I’d progressed.
I am reserving judgment, but I so far I prefer Trials to the current Dungeon. I still play it every day, just for the jewels, which means that 90+% of the time I am being told that I’ve failed because I didn’t get a perfect run. I don’t need dragonite any more, just let me play for jewels without the negative feedback.
This is want they want. Plain and simple. They’re laughing at all the complaints that they knew would come, and complaints they knew would be justified. They can g f themselves as far as I’m concerned.
Based on other responses, I was concerned that I was promoting a strategy that wasn’t actually useful. I cleared level 3 just using skull damage, but it took multiple attempts. Level 4 was not working until I switched to this. 
