I need a hero ability that increases attack range by a certain amount every level, and I can't seem to find one that could be used in the editor. Suggestions?
You mean like the DotA Dwarven Sniper's Take Aim ? Make an upgrade based on black gunpowder. Then Make a passive ability that does nothig. And make a trigger when the hero learns that skill :
Player - Set the current research level of Black Gunpowder to (Level of Take Aim for (Learning Hero)) for (Owner of (Learning Hero))
Remember to add your upgrade in Techtree - Upgrades Used for your unit. Diffrent abilities like that just have to use different upgrades.