Continuing with the 4 star only challenge for this current cycle of trials.
This was a relatively tough one for me because I severely lack good hitters for this trial, most of them are support heroes. Anyway, finally I decided to go with the following team. Kasshrek provided some much needed healing to keep Proteus and Sumitomo alive. Boldtusk for heal and attack buff. And CaedmonC was used as a secondary hitter and cleanser. I thought the team composition was good enough.
The mob waves were farily simple, and I had a okay board setup before entering the boss wave. I wanted to try doing it without using any items, but for some reason all the bosses started targeting only BT (which I found rather weird). All the small heal potions I used were to keep him alive. Proteus kept blocking their specials intermittently as and when I was able to charge him up. Took out Oberon first to ghost tiles, then targeted Balthazar and Ulmer was the last to go down. Had to use two bomb attacks to keep the bosses’ attack power under check. All emblems and trainer heroes hoarded for now. 
