I applaud your changes to the healing costs and decreased damage received from boss fights, not to mention how much time left before the next health tick comes.

However, your world boss is another story. LOL. Do 290M damage in 5 days? LOL. That's like killing the Robert Lee boss in an hour and every hour for 5 days. If this were an arcade game, it'd be called a "quarter eater". How about increasing the time to kill the boss from 5 to 10 days?

Just a thought before your world boss idea becomes a fiasco....