The initial 20+ sketches (thumbnails)

I came up with three main conspiracy about black death. Aliens(which is always an option), the punishment of nature, the punishment form the god and the coming back of the pied piper (which come from a European fairy tale).

Basely, all my sketches have an same issue about having a too-large scale.

This piece was drawing in A3 size. It is supposed to illustrate that some evil guy who wearing a suspicious mask manage to circulate the fatal disease through trading with European. 

The one on the upper-right is a metal flea. It suggested that somebody has advance technology intends to attack the European society. That was supposed to be a story under a steam punk background.
Then the one one the upper-left is simply means the punishment of the god.

The sketch on the lower-right is showing that the triangle of human being on the top of the pyramid  is just too large that destroy the balance of the ecological environment. Then, the mice with wings are trying to destroy it, which means that mice are the angles were ordered  to destroy human being.