Beings of Tash Kalar
This and Swordmaster were amongst the first beings created for the game and they were meant to be "regulars", i.e., line soldiers, and that's why they appear in a straight line of your pieces. The theme shifted a bit during development, but this remained.
I think you see what is going on from the picture, right? The Axeman appears and while landing on its summon space, it kills a piece (even heroic) on a nearby space by one mighty chop of his axe.
As an aggressive two piece pattern, Axeman is very useful in initial phase of the game. If opponent ignores the fact you may have it in your hand and goes for close combat, you can destroy two of his pieces on your second turn. Later in the game, the ability to destroy also heroic token may be useful, but it is rather weak being and I suggest cast it even with weak or no effect, to draw a stronger card.
The history of the Axeman is highly tied with the Swordmaster. They started in the original deck, and their effect was just to kill a orthogonally/diagonally adjacent common piece. When the original deck split into Empire and Highland, their ways parted, but the effects remained similar. I just added an option to move to the destroyed piece's square to both cards, to strengthen them a bit. And later, their effects were altered to strengthen the theme and distinguish the schools – the ability to destroy heroic piece to aggressive Highland, and the ability to promote the Swordsman to noble Empire.