Have been killing these for quite a while and have yet to see a lt blue one at 70. Even my 70 druid, using track, is unable to locate a lt blue seething mist or steam drake.
As noted above, they can quad and triple often and stuns seems to happen a little more often than I have found with other mobs this level. Most can be pulled single if you time them correctly. I have seen hits in the high 700s from the seething drakes and Dranadune (named) in the mid 800s.
I have yet to see a ruby with 100+ kills. Hopeful though.
Tiggoi 70 War
Tremil 70 Dru
Sapium 69 Clr
Oaus 69 Bst
Layla 68 Shm
Laroux 66 Mag
and so on...
The Nameless (formerly Inny server)

Ash Covered Hide
Ash Covered Scrap Metal
Ash Covered Swatch
Dirty Vellum
Drake Blood
Drake Egg
Drake Intestines
Drake Meat
Drake Wing Bones
Drake Wing Webbing
Grimy Fine Runic Parchment
Pearlescent Drake Claw
Steamvent Ruby