I suggest not making copying diablo with seasons!

Instead of making your seasons like diablo, (the reason most of us dont play it anymore), let map levels go up indefinitely. You do a level 20, enemies drop 20s, you combine for 21s... the uber bosses can set to different difficulties up to +/- 10 levels of character and the atlas tree adjustments. Seasons would be more like a reset that still plays in the same realm but have a special title, and only those reset characters can compete in the challanges. More Like how you prestige by choice in call of duty games, but can still play with your friends. Many players quit playing weeks before the reset as it becomes a waste and most people im talking to are not going to even start the new season.