All right:
#1 Give some more Ideas of your own to it. What kind of effects should it have?
#2 If it is a hero, WHEN does it cast the spell? On wave spawn? When all units of the wave are spawned? When first tower hits a creep in that wave?... So many different choices here. Each with its own good and bad points
#3 What general Idea should be behind the spells? Only supportive? Does it have to hit Creeps (armor reduction, slow etc) or can Towers benefit from it? (Like giving every tower [waveround+5]basedmg bonus for 10 seconds)
#4 How many Spells do you want to have and should he get a chance to "fail" (Maybe 10% chance to miss, -1% misschance per life lost the round before)
#5 Spell should hit what? Are there AA spells or spells which can hit Challange creeps?
#6 Do spells have fixed values or Wavedependant values?
Well guess, there are some questions for you ^^
To give you an example:
Supportive Spell: Mist of Greed
The Hero casts a Dark mist of greed (Dark particle effect on the map) on a random point on the map which covers 1 range of the impact point (so total of 3x3 fields).
Every creep which dies in the vortex got a 15% higher chance to drop an item. (Stacks with Black Widow Aura! same source).
The vortex lasts until the next wave spawns OR you press the Skip button!
Gets Cast when round starts AND the last unit of the previous wave dies.
That be cool I had idea a card that give you a % chance to draw another card so some rounds you draw two cards that be cool but not I high % just somthing that would help your hand out some
Yeah I think so to it would help out your hand dont need to be high % just 10% chance to draw another card
Reminds me of Magic "Tap the Elven XXX to draw another Card from your Deck to your Hand" ^^
But i would like to see somethin like:
1% for Creeps and 10% for bosses/Challanges ^^
since we are talking about a hero it starts on round 1. Dont forget it =)
But to be honest, i would like to see 1-3 more races first =)
More towers, more choices and of course, somethin which can beat the shadow ;D