As mentioned last week, Shattered Pixel Dungeon's upcoming Cleric hero has a variety of unique spells which they can access via their holy tome. The first of the Cleric's spells is a simple supportive ranged option: Guiding Light.
Guiding Light is an innate spell (no talent needed to unlock) and does some damage while 'illuminating' the target. This guarantees that the next physical attack made against that target will hit.
(Image Description: a short GIF showing off the guiding light spell. The Cleric casts it on an enemy, which begins to glow. The Cleric then waits for the enemy to approach, and attacks them.)
Yeah, unfortunately it's just not really feasible to add. The whole game is designed around one player and lots of things would break or not play well, and that's before the trouble of adding networking code.