I think custom heroes are spawned in the middle of the map along with the survivor at the beginning, instead of summoned from the command center like all other heroes. It's not a big deal, but it might be nice if custom heroes were summoned from the command center instead.
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I've attached here a small map with this feature included. I can't seem to attach the map file. Is there some way I can do this? The player has a command center from which he can summon three generic heroes as well as his custom hero. He can summon the generic heroes at any time, but he can only summon his custom hero once the he types "code". If this was implemented into the game, a donator's -save code would be the actual password. (I'm not sure how the fortress codes work, but I couldn't test this out. It might be pretty easy, or it might be near-impossible.)
Each donator (Bob, Steve, and James) has his own custom hero.
The map description gives the basic instructions, and the comments in each trigger give more detail on the scripting behind it. If any of it isn't clear enough, I will be happy to elaborate.
It wasn't too hard to get the code to work for one player, but it would probably be a lot tougher to make it work for ten players. This is a pretty minor feature with potentially a lot of work behind it, but it might be a nice touch to the game. Especially so if a new player is ready to summon his first hero and sees the (grayed-out for him) option to summon a custom hero and he's really impressed by the opportunity to get one, and by the attention to detail.