Juubi said:
Sadly, my characters aren't even up to handling Torment yet. Much less anything special, if seasons are special.
The only difference between normal gameplay and Seasons is that in Seasons, you start from scratch, as if you never played before. So no Paragons, no maxed Artisans, no Followers, etc). It all has to be unlocked again.
The saving grace is, of course, if you have Adventure Mode, which will unlock your Artisans and Followers (though you still need to build them back up). Otherwise, playing the Season is the same as playing the normal game.
Once the season ends, your Seasonal characters will be converted to a normal character. They'll get access to all the normal things, like your previously-acquired Paragons, etc, and anything you unlocked in the Season that you didn't in the normal game (achievements, higher Paragon levels, artisan unlocks, transmog designs, blacksmith plans, etc) will also get transferred over to your normal game.
Seasons DO have unique items that don't appear in the normal game, but those unique drops will be put into the normal drop tables at the end of the season. The only thing you have a chance to lose is the exclusive transmog plan that each season will let you unlock. To get that, you only need to reach level 70 with a seasonal character. That's fairly easy in Adventure Mode; my brother and I are 5 levels away from it.