Ender Dragon - Impact On The Overworld

It would be great to have some CONTEXT for the Ender Dragon in the Overworld, i.e. some physical evidence of the Dragon's existence to create an incentive (and reward) to defeat the dragon (apart from just the XP).

This could be in the form of ENDER BLIGHT, which impacts random areas of the Overworld. One effect is the spread of Mycelium, ruining crops and fields. Another impact could be the spawning of Shulkers, who overrun villages or other structures. When killed, Shulkers do NOT drop their shells, which disappear back into the Void. There could be a higher incidence of Endermen, with a more aggressive attitude, focusing their "block removal" antics on sections of buildings and fences rather than just a few blocks of grass. Lastly, there might be a new hostile mob loose in the Overworld until the Ender Dragon is defeated, something related to the Void, like packs of Void Wolves which are utterly black but filled with stars, like the Ender Portal.

After the Ender Dragon is defeated, all the Mycelium turns back to grass, the invading Shulkers are banished (leaving a few random shells behind which don't de-spawn), and Endermen become neutral again, unless you look them in the eyes, which still angers them.