... Cause heroic types to beeline for them, to purposely engage them. Think Dwarves to Barricades, or Diggers to diggable rock.

For example, if I create Liches and Demons off the beaten path, Knights, Priests and Vanguards will ignore routes to the Portal, specifically to fight those creatures.

Different creature types could be added, which tempt different enemies.

In this way as well, entity traps can be placed *without* interfering with regular killing zone mechanisms.

With this in mind, I might even set up separate Trap slots just for entity traps... depends how far in this direction you might wish to go.