It is a spell that kills all units not next to another unit (isolated units).
Thanks to Jackson Tjota and Mario Wibisono for the tips!

An illustration done for Zems Online Card Game.
Culling the Stray copyright 2017 by Impulse Limited.
For more info on Zems, please visit the links below:
Zems Official website - www.zems.com
Zems Facebook page - https://www.facebook.com/zemsgame
Zems Twitter - https://twitter.com/zemsgame

_____________________________
INSTAGRAM: www.instagram.com/deivcalviz/
PORTFOLIO: www.deivcalviz.com
TUTORIALS: https://gumroad.com/deivcalviz
FB: www.facebook.com/DeivCalviz