The revised monster math

[S'mon]

For 7 level 9 optimised PCs a level 14 Solo looks exactly right to me, and Calastryx's low AC makes her pretty well perfect. PCs not hitting all the time is important for boss fights to feel threatening.

My 7 PC level 9 group (not great optimisers, and I limit sources) had a great fight with Emerald Dawn, an adult green dragon, level 12 solo, and managed to kill her. I halve all monster hp and the fight still took a couple hours. I had previously defeated the party of 5 level 9 PCs with Nightshade, a level 11 adult black dragon - 3 dead, 2 escaped.

 

[pemerton]

When I ran Calaystryx condition-lock (immobilisation in my case) was certainly an issue.

 

[GordyK]

Monster Vault: Threats of Nentir Vale is probably your best bet here. Has lot to offer in Paragon Path as far as epicness.

 

[Storminator]

Had the fight yesterday. First half the dragon flew everywhere, slide everyone around (including two off a cliff) and generally scared the pants off them. Eventually they immobilized it and fought it down. Pretty much exactly how I hoped it would go.

PS