Hmmm but still I'm bit confused because I never used Aetherial Crown and the ring...But how do you get both of em?Because on the wiki's if you choose to be a Vampire,you only had 2 legendary rings,but if you are keep being human/remain as werewolf,You get Aetherial Crown

The question is,How do you get both item?

Thanks Vazgen
and 2 More question

1.How do you increase perks progress as a Vampire Lord
2.Is it hard as a Vampire?Because every Sunlight you'll weakening,and not strong fight against your foes.Or after the ending find a cure?

1. You get new perks when you kill enemies using your vampiric drain spell or power bite attack while in Vampire Lord form. 

2. Adrik doesn't suggest staying as a vampire in a build. So I guess you'll do good to cure yourself after the questline.

Staff Of Magnus doesn't absorb health?
are these a bug or something?
cause I had foes (bandit) and didn't drain health

The ingame description says:

The Staff of Magnus Section elaborates on this statement quite nicely. 

It might be fixed with the official/unofficial patches. The discussion on UESP page has it unconfirmed: link

I remember that, and I'm almost certain that at that time the UESP article on the staff had it mentioned in the bugs section. It's not there now