I can give you another voice for the Ancient Spirits Of Evil:
Robert McFadden in “Excalibur”
Merged Post:
I thought he was voiced by Robertb McFadden?
I thought so, too. Moreover, he sounds the same to me in both episodes. I will double check, though.
Almost. That’s Nemesis in The DoomGaze, not the ASOE. But Hyman does voice them throughout most of the second season.
That’s right! They really couldn’t make up their minds, could they?
So at this point, thunderianroyalguard has three and LiamABC has one. I still want to double check the sound of Char’s voice. Also, there is one more character that hasn’t been mentioned yet. I’ll post it when I follow up on the Char answer, if no one else has mentioned it by then.
In the meantime, you’re up, thunderianroyalguard!
UPDATE:
I just checked. While I’m still 99% sure it’s Robert McFadden as Char in both episodes, the confusion is justified. He sounds slightly different in each episode—he’s gruffer and more Slithe or Molemaster*-like in “Return to Thundera” (probably because he’s píssed off at Snarf the whole time), and uses more of a normal speaking voice in “The Heritage”.
- Credit and my thanks to LiamABC a few pages back for correcting me on McFadden as Molemaster, as opposed to Hammond. It’s totally him.
I always saw Char as the last link in the long, long chain of McFadden voices that connects Slithe to Snarf.
Well, Doug Preiss also voiced Alluro, and I hear a lot of similarities between those to characters… but anyhoo, I’ll think of a question and post it asap!
We should go through and capture audio for all of his voices, and then string them together. That would be quite a task!
It was only when I heard him as Char that I was able to accept that he was both Slithe and Snarf, as this voice does link Snarf to his other more in-between voices.
Similarly, it was only when I saw Larry Kenney being interviewed on the DVD and switching between voices that I finally accepted that he was both Lion-O and Jackalman. Earl Hammond is another instance, it was only very late on in the run that my ears accepted that he was Vultureman as well as Jaga and Mumm-Ra.
Your ears are better than mine—I still can’t quite hear (or fathom) it.
I forgot to mention the last character to be voiced by two people, though now that I think about it, I think I’m wrong! I was looking for Snarf Oswald—we see him briefly at the beginning of “Feliner”, voiced by a goofy Earle Hyman. When he reappears in “ThunderCubs”, his voice is completely different. But it’s still Hyman. Oh well. 
Is it the Driller? Is he Robert McFadden and Peter Newman?
No—he’s Robert McFadden in all three of his episodes.
Again, I was confused on the whole Snarf Oswald thing. To make matters worse, in “Feliner”, the snarf I was thinking of isn’t even identified as Oswald, and looks a bit more like Egbert!
If you can think of more characters, great! But I have no more in mind.
So does this mean it’s Thunderianroyalguard’s turn now?
Yeah, it’s my turn! Well, I couldnt think of a difficult one, so I’ll do an easier question:
How many and which episodes were written by Jules Bass??
Next time I’m up I’ll do a harder one
Crew questions are hard enough for me 
This one is hard, or at least tricky, because Jules Bass wrote under a pseudonym! And I only know that because of David Chichton’s book.
The pseudonym is Julian P. Gardner, so the episodes are:
Trouble with Time (co-written with Ron Goulart)
Pumm-Ra
The Terror of Hammerhand (co-written with Ron Goulart)
Garden of Delights (co-written with Barney Cohen)
HA! You are correct, Sir! See, not that hard 
You´re up TZF!
Interesting! I didn’t know about that. As soon as I saw the question, I thought, “I never saw Jules Bass’ name on the writing credits - did he use a pseudonym?” - then when I saw what the pseudonym was, I recognised it instantly, because those first two episodes basically complete the establishing story arc (that is to say, I regard the first six episodes as the full set-up for the whole series, rather than just the first two or four).
I feel like they also have a certain vibe that gets diluted as time goes on (or, rather, when Leonard Starr and Jules Bass stop contributing). It’s like a darkness, or a sense of desolation about Third Earth that doesn’t last much past “The Ghost Warrior”.
Okay, new question.
Which characters are related to one another? I can think of fifteen families or sets of relatives (siblings, spouses, couples, parents-children, etc.), so whoever gets the majority wins. And if you say Tygra and Bengali, you automatically lose.
Lol at Tygra and Bengali. Let me think:
[ul]
[li]Wilykit and Wylikat (duh)[/li][li]Snarf and Snarfer (double duh), and Oswald and Eggbert.[/li][li]Claudus and Lion-o (triple duh)[/li][li]Willa and Nayda[/li][li]The unicorns keepers (husband and wife)[/li][li]Luna and Queen Luna[/li][li]Robear Bill and Robear Belle (not 100% sure)[/li][/ul]
Great job, Tygra_Rules. These were seven of my fifteen, so someone else could still potentially win.
I can only think of a few more in addition to “Tygra_Rules” list:
[ul]
[li]Ratar-O and Ratilla
[/li][li]Wollo traveller and his daughter
[/li][li]Leah and her parents
[/li][li]Ice King and his deceased wife
[/li][li]Hachiman and his ancestor (Nishida, I think was his name)
[/li][/ul]
[ul][li]Wilykit and Wylikat (duh)[/li][li]Snarf and Snarfer (double duh), and Oswald and Eggbert.[/li][li]Claudus and Lion-o (triple duh)[/li][li]Willa and Nayda[/li][li]The unicorns keepers (husband and wife)[/li][li]Luna and Queen Luna[/li][li]Robear Bill and Robear Belle (not 100% sure)[/ul][/li]
[ul][li]Ratar-O and Ratilla[/li][li]Wollo traveller and his daughter[/li][li]Leah and her parents[/li][li]Ice King and his deceased wife[/li][li]Hachiman and his ancestor (Nishida, I think was his name)[/ul][/li]
Some more:
[ul][li]Hachiman and his wife[/li][li]Torr and his family[/li][li]Malcar’s adoptive parents = husband and wife[/li][*]Snarf’s aunt Esmeralda[/ul]