[IAmBatman]

Here's a bit on the Axe from the DC Wiki:

The Electro Axe emits a yellow-hued energy that, when struck against a surface, disperses and spreads continuously. The energy is seen capable of infecting human soldiers, turning their skin into a rough, pale grey tone, while lengthening and sharpening their teeth, seemingly transforming them into the Parademon soldiers of Apokolips.

So how about something like this?

ELECTRO AXE INFECTION
Instead of attacking with Steppenwolf, you may choose any enemy figures within X spaces of him where X = the number of Wound Markers on this card. One at a time, roll an unblockable attack die against each chosen figure. After destroying a figure with this special power, you may immediately place a Common Parademon in your army on the space that figure occupied.