Any thoughts?

Beguiler is good if you are making a cipher focused on cc and party support. For damage yeah Ascendant. 

Depends what you mean by "viable." You can beat the game with any cipher I expect, even on PotD.

I like a single classed Beguiler. He not only gains +5+PL focus when using deception spells on targets that have an afflcition or are flanked, but can also regain focus when he crits with a spell (like other ciphers that take "The Complete Self" as PL7: chance to regain +5+PL Focus on crit with a power). In combination with "The Empty Soul" (+10 ACC with powers vs. Will) and "A Soul's Echo" (15% hit to crit vs. Will) you can fill up your focus very quickly when casting Deceptions spells. "Shared Nightmare" can make sure you hit/crit a LOT of enemies with your deception spells, giving you back +5+PL focus per enemy hit and +5+PL when you crit for every attack roll in the AoE.

I like a single classed Beguiler. He not only gains +5+PL focus when using deception spells on targets that have an afflcition or are flanked, but can also regain focus when he crits with a spell (like other ciphers that take "The Complete Self" as PL7: chance to regain +5+PL Focus on crit with a power). In combination with "The Empty Soul" (+10 ACC with powers vs. Will) and "A Soul's Echo" (15% hit to crit vs. Will) you can fill up your focus very quickly when casting Deceptions spells. "Shared Nightmare" can make sure you hit/crit a LOT of enemies with your deception spells, giving you back +5+PL focus per enemy hit and +5+PL when you crit for every attack roll in the AoE.

So, I could run a single class Beguiler effectively...hmm.

That is totally up to you.

 

I merely showed some advantages. The high level stuff also works for any other cipher who uses will based spells. Doesn't need to be a Beguiler. But the fact that nearly all deception spells target will and you can get 10+2*PL focus per crit is kind of cool. I used the Beguiler for CC mostly and almost never ran out of focus after a certain point.

That is totally up to you.

 

I merely showed some advantages. The high level stuff also works for any other cipher who uses will based spells. Doesn't need to be a Beguiler. But the fact that nearly all deception spells target will and you can get 10+2*PL focus per crit is kind of cool. I used the Beguiler for CC mostly and almost never ran out of focus after a certain point.

Testing out a Seer (Beguiler/Ghostheart). I like it so far, good CC.