I have only had a chance to listen to the tracks on myspace and the albums at work on a shitty headset, so my opinions at this time will not be fully formed. Hopefully I will have a chance to listen to both of them more attentively when I get home from work later.
Keeping in mind the above, here are my observations. Firstly, I do not see any real resemblance to Drudkh, other than the vocals on the first album, and that both are Ukranian. Musically, they are quite different, as Keys/Synth add a very different dynamic to music. I think Burzum, mentioned in the title, is a more apt comparison in terms of similarities. Drudkh oozes a strong sense of misanthropy, slow and menacing, though the prone to quick bouts of anger. For Darktale, to be honest, Flame Shredding the Skies at the beginning in particular reminds me of a sound akin to Dimmu Borgir's "Enthrone Darkness Triumphant". I wonder how many people are now scarred with this revelation.
. Only that part though really, On a Crystal's Wing is quite varied between the songs.
Regardless, the vocals on the first album set the bar pretty high, and a change would obviously turn people off. Feeling more comfortable with his music, he wanted to venture down the path of his own vocal style to impart his own essence on the music. The first album, regardless of the music, exudes the feeling of strength, power, and an even epic or majestic tone. 1:40 into "Resinous Blackness of A Skies" however reveals much more depraved vocals (this isn't the only time in that song, just an example). Judging from the second album, these parts are sung by Astaroth.
If it is him then, why was this not continued on the second album? Crimson Velvet's comment about the effects is entirely accurate. Those effects used to create the illusion of distance is what really ruins the vocals. Clearer, and more focused, with an emphasis on what I heard in that specific part of "Resinous..." would be brilliant. With proper use of vocals and guitar, an overwhelming atmosphere can be created without the use of keys/synth at all. As I do listen to melodic black metal, I do appreciate keys, but the less is more approach generally is best. There are a few parts where I find myself wishing the keys simply did not exist in the music at all.
The second album has a much stronger doom vibe. I'll have to listen to them a few more times to form a better opinion, but I think the second album is the stronger of the two, regardless of my feelings about the vocals. Really, there aren't enough of them to sway me into disliking the album because of them.