So what is your ultimate 5-deck team from the hereos you currently have unlocked?
Goram - goes without saying, one of the best tanks in the game. Can absorb a lot of damage, has can divide into 4, has life steal and also a shield ability (awakened) - one of the best all-rounders in the game.
Malrath - like Goram, he is also a tank that has lifesteal and can absorb a lot of damage. Many times I've been down to 1 vs 3, and Malrath has taken them all out. I'm currently working on awakening him, another great tank for your team.
Nilya - Glacial Spikes is a devastating move and can change the momentum of the duel and put you on the front foot if you are trailing.
Sylphi - A magic hero with great normal attacking moves, not to mention her specialty. There have also been many times when Sylphi has been outnumbered in a battle and remained the last one standing due to her great attacks and random life steal.
Firehawk - This guy is fantastic. Some say that he becomes useless once you hit level 90. I'm level 93 and he's still in my first team. His ultimate has no limits and will hit anything in it's path. I find that he is one of the best backline heroes in the game. The only downside is that his specialty costs him his life after a maximum of 3 regenerations.