Like most things, there are pros and there are cons.
The most obvious benefits to your main account are that upon your first ascension you will have a fixed 5% stat bonus, rising to 10% on your second ascension (to Prophet), then 15% (Messiah), 20% (Incarnate), 25% (Living God) and 30% for the 6th ascension which is only known as Living God +1. There are 23 ascensions in total, and anything after the 6th only provides an additional one percent bonus on top.
You get a nice red title under your name indicating that you are ascended (and which level).
You get to play the ascension server and pit your wits with the finest players in the game.
One the down side, you have to maintain the upkeep of your ascended account to prevent being descended on the ascension server which in turn will reduce your stat bonuses in main for a 2 week period (You can not go down in ascension level however - A descended Prior will not just become a regular unascended account).
It can be quite confusing for some, the numbers are greater and the mechanics of the game are different. Other than that, not much else to report.
For more information I strongly suggest you read the Ascension guide here on the forum which can be found here
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