This is just a rough idea for a unique hero, I haven't played nearly enough to know what to use for the numbers.

Trickster:
Primarily an agility unit that looks like a cross between Nymphora and Voodoo Jester and has a laugh like jokey smurf.

Skills:
Trick:
Kills target NPC and creates weak illusion of trickster.
When illusion dies it spews green goo and enemies near it are slowed for X/X/X seconds.

Acrobatics:
Passive evasion of X/X/X%
A small amount of mana is gained for every missed enemy hit

Jack in the box:
Spawns a box at target location
After 2 seconds box opens and does one of the following:
If there are more allies near the box than enemies then ALL units in area are healed for X/X/X
If there are more enemies near the box than allies then ALL units in area are damaged for X/X/X
If there are the same amount of allies and enemies near the box ALL units in area are briefly stunned

Straw man (ultimate):
When activated creates a weak straw dummy at current location.
When de-activated trickster trades places with the dummy.
If dummy is killed before the swap Trickster loses health (and ability to swap)
If dummy is killed after the swap enemies around dummy are damaged for X/X/X