[General] Hero Defense waves help. please and ty

[Xion]

Hello everyone. I have a trigger right now that spawns 2 types of units(5 footmen, 4 archers) every 30 seconds of game play. I need help with creating a trigger that makes the waves stronger as the game goes on. I would like that the waves get stronger every time a hero on the team reaches a certain level. So each time the first hero to reach the certain level on a team reaches level 10,20,30,40,50,ect the units that spawn will be stronger then the previous ones. I cant seem to figure out how to make it upgrade the units like that. Whether the creeps get stronger by replacing them or just upgrading their hp,atk,armor i dont mind. Which ever way is better for any of you to help me. Any help would be appreciated. Thank you.

 

[Tickles]

Maybe this will give you an idea. It just uses one simple upgrade to cover all of the stat bonuses.