Need 1 spell +rep

[Dr. House]

I need a spell that lets an archer hero create a pentagram of arrows around a unit when used and than let the pentagram explode. here is an example of what i mean

Hero name: Ishida

Ability: Pentagram of explosion

Arrows are fired around the enemy creating a pentagram than after 1 second it explodes and deals damage.

If somone can make me this spell he gets +rep and credits in my map