I did it 2 days ago.
Virion (45), Avalon (50), Elena (45), Gan (45), Bane, Cleo, Gafgar, Yip
The main problem of this and further levels is a dragon with high HP, and he often (almost always) goes straight to your archers and kills them (they are main dps if you have no maxed Mako).
I personally have no good Mako at the moment, but he can deal up to 2-3 million damage for a fight, if you max his might, level and passive skills for damage.
anyway, I did it without him.
Summon skills has to be maxed for all summoners. Also you need to be in a Human race so summoned troops get all research.
Gan needs Life Force to prolong summon time. I also used his 1st skill to cause debuff to enemy troops and delay them at some point.
Also used items on summoners that prolong summon time even more (5 seconds).
Started with Yip tornado or Cleo's black hole (second I think is better).
Virion is better to have a high level of his shield too.
Same goes for Gafgar.
Bane is better to put a little behind, because he dies too fast, his best role in this is to take dragon's attention from coming close to archers.
BUT again: if you have a chance to use Mako with almost maxed stats\level\abilities and good items for might- he will kill the dragon without any problem/
Void - 120, Abyss 495
House: Icarum, Gods of War