The only change is Grimm level, it was 3/60 in the last Trials of Survival
I do not bring full carpet bombing this time, but still have bombs and dragon attacks.
Fortunately, the final bosses HP are only slightly above 3600, thus bombs and dragon attacks are enough to bring them to critical state. That way I can use axes slot and fill it with another health potion to compensate for the lack of healer.
In the end, I only use the potions, 3 bombs, and 1 dragon attack. This is the most economical trial for me.
Grimm 
At last I complete the last stages of every trials, this was the last trial which I cannot complete due to level requirement.