Ok so:
Ascension: Needed: Lvl30+ esper & Ascension orb (drops from bosses)
Result: Ascended esper, with higher stats (white & green), reduced in level though (35->28, 30->1)
I will post my stat increases when I'm home, but they're very nice. Also, ascending at 35 is better than 34, 33, etc. It works a bit like ascension 135 vs 150.
Esper will look differently. Any esper can ascend.
FusionNeeded: 2x ascended esper (main + sacrificial) & esper fusion manual
Result: I'm not sure about this one. As I read it, it should transfer skill effects from the secondary esper to the main one. But there's also stated that you randomly get 1-8 extra effects. So im not sure how those effects are determined. Especially when I look at espers that don't have 8 possible effects:-? (like most of them). So this one is still a bit blurry for me. You can accept/decline the changes, but the secondary esper will be destroyed nonetheless. When you reach 8 extra effects, the visuals of the esper will change again. Fusing will not affect your esper's stats afaik.
InheritanceNeeded: Asc. Esper & Sacrificial (non-asc) esper + tome/acc of that esper
Result: Asc main esper with extra esper skill. This skill will appear in the second esper skill slot.
The skill level will be +2 cuz you used the acc/tome in the process. So minimum lvl3, max lvl5.
Secondary esper will be sacrificed, as well as tome/acc. This won't influence your main esper's stats as well. Max 5 extra skills can be added.
About the mysteries, I'd like 2 gambler cubes then please^^
And concerning other espers... If you're interested in a silence skill, I got a lvl2 Taen+tome/acc
Linky. I already have a good silence skill so i dont need it. Modo 105 esper is nice too to inherit. Fan of bard would be nice for you too (extra dmg based on sp). Oh, and spirittrap banner is kinda nice too for pvp. Here's an overview of all the espers:
http://jd-wiki.perfectworld.com/index.php/List_of_Espers