@admin.register(Hero)
class HeroAdmin(admin.ModelAdmin, ExportCsvMixin):
  change_list_template = "entities/heroes_changelist.html"

def get_urls(self):
  urls = super().get_urls()
  my_urls = [
    path('immortal/', self.set_immortal),
    path('mortal/', self.set_mortal),
  ]
  return my_urls + urls
def set_immortal(self, request):
  self.model.objects.all().update(is_immortal=True)
  self.message_user(request, "All heroes are now immortal")
  return HttpResponseRedirect("../")
def set_mortal(self, request):
  self.model.objects.all().update(is_immortal=False)
  self.message_user(request, "All heroes are now mortal")
  return HttpResponseRedirect("../")

{% extends 'admin/change_list.html' %}
{% block object-tools %}
  <div>
    <form action="immortal/" method="POST">
      {% csrf_token %}
        <button type="submit">Make Immortal</button>
    </form>
    <form action="mortal/" method="POST">
      {% csrf_token %}
        <button type="submit">Make Mortal</button>
    </form>
  </div>
  <br />
  {{ block.super }}
{% endblock %}