Seeking advice on a Dark/Rad/Stealth build

[CybotMike]

So I realize I may be asking for a sub-optimal build here, but I have a character concept I love, but am terrible at calculating defenses and recharge rates.  I love the Dark Blast offensive set, but normally hate how End hungry it is.  But taking a page from one of my favorite Defenders, AM and Radiation Emission always helps End issues.  And building the character, I loved the idea of having Stealth on him (no intent to dip further into the pool, but personal stealth on this Corrupter sang to me).  The only other real request I have is Fly as a travel power, because as much as I think it's overplayed, I've seen in TFs how critical it is.

 

With all that in mind, how would you build this?  I would love to hear all your ideas.