A Ruby Dragon is fought during a particular Lagunadream sequence. While shooting a movie at Vienne Mountains (with Laguna as the protagonist), a Ruby Dragon wanders onto the set in place of Kiros in a dragon suit. Both Laguna and the director mistake the dragon for Kiros, remarking how realistic the "costume" is. Upon realizing the dragon is real the director flees, leaving Laguna to fend it off with a gunblade before fleeing himself, only to encounter, battle and defeat it alongside Kiros a minute later.
Ruby Dragons are easier with only two party members, as then they don't use their devastating Breath attack, a non-elemental physical-based attack whose damage can be halved with Protect and defended against by junctioning a high-level spell in Vitality, such as Meltdown. Ruby Dragon will only use Breath if all three party members are alive. This also applies to Meteor and Firaga. So if there is at least one KO'd character, the dragon will only cast Fira and Aero.
Ruby Dragon is susceptible to Sleep, which can be exploited. Having Sleep junctioned to Status Attack is useful. Irvine is handy to have around against a sleeping Ruby Dragon, as his Limit Break, Shot, doesn't count as a physical attack, and thus will not wake it up. Demi is another good move to use while it's sleeping.
After acquiring the TonberryGF in Centra Ruins its LV UP ability can augment Ruby Dragon enough for it to have Flare and Meteor in the draw list. It is advised to have high Magic (above 100) to successfully draw 9x Flare and Meteor per command.
[view·edit·purge]A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). It is the birthstone for July. In this instance, the word ruby refers to the dragon's color.
[view·edit·purge]A dragon is a legendary creature, typically with serpentine or reptilian traits, that features in the myths of many cultures.
Its Japanese name translates to Rubrum Dragon. [view·edit·purge]Rubrum is Latin for "(the) red".
The colored dragons in Final Fantasy derive from Dungeons & Dragons, where red dragon is one of the chromatic evil-aligned dragons, and gem dragons are neutral, Sardior the Ruby Dragon being their deity.
Ruby Dragons are not usually fought at Vienne Mountain area, yet Laguna runs into one when filming a movie. Ruby Dragons suddenly appearing at the mountains may be because of the implied Lunar Cry near the area that left behind the Trabia Crater, induced by the Lunatic Pandora Laguna spots in the dream.