The 'Seven Flames of Odin' achievement level I, and level II.
I trained tens of millions of tier IV's, V's, VI's, and VII's. I ran a 3rd level Tower of Odin and stronghold siege for one of our CVC tournament events. We slaughtered over 298 million Plarium Jotuun troops in only four marches, using the following Melee and Range tier troops: tier III's, IV's, V's, VI's, VII's. I logged off and 3 hours later, I received my "Seven Flames of Odin" level II. And our clan only lost 64 million different tier troops. I would assume that any player will acquire the "Seven Flames of Odin" level I the same way, as if I remember the way I did correctly though.