the trap deals less damage than Rain, but it also consumes less mana, and even 2 Minions will deal damage no worse than Rain.
you won't have to spend anything on leveling up the hero; anyway, you're leveling up Summoning, so you're leveling up the traps at the same time.
leveled-up traps are almost as good as Eemba.
Crash Boys – that's how I refer to Orcs; those in the know will understand.