I just finished mine about 2 weeks ago,
Isle 5, I got the drop from them second bird we killed, Remember when you engage the Spiroc Lord he dts every 45 sec, also when I did it he kept insta repopping if that happen sirran will attack you, best bet is to die have necro get sirran away from Lord and FD and rez ya after he loses aggro. after you get your keys you can invis past the Lord.
Isle 6, Well I say is i hate BZZATs! the isle starts with 3 you kill 1 it splits, basically you can mas slaughter it all but leave the Bixie model i believe called Bzzzt alone till all others dead and ya ready for the Named DT mob. Once Bzzt dies Bzzt Bzaat or something like that will spawn and immeadiately DT someone , and will do so every 45 seconds.
Now that she is Dead Sirran will spawn, This Isle is Backwards, to get him to Talk to you instead of Hail, Sirran the Lunatic you Say "Citanul eht Narris ,liah" To spawn the Sister on Isle 7 say "llaw eht htiw eno ma I" you best bet is to leave someone on Isle 6 sayin the Hail phrase to Sirran Every 20 seconds or so to keep him there.
Isle 7 ,
Start by killing the 15 Drakes, once those are dead start on the 7 Sphinx, They have an initial DT then they are easy, Thier aggro Range is also quite small so stand back cast take the DT then have others kill it, Rez up rinse and repeat 6 more times. Congrats now the Isle is clear except for the sister. She is a DT every 45 sec mob again. So stand Back Cast and burn here down. Sirran will then spawn, Note IF the piece did not drop have the necro aggro sirran and pull him far away and FD. Then have you person on Isle 6 respawn the queen. R^inse and repeat till you get your drop I only lost about 15% reg XP with 96% rezzes in my 3 days in sky but the Ring is worth it
Also This may prove quite Helpful
http://home.comcast.net/~drexxell/eq/planeofsky.html