Dragon Install is the name of Sol Badguy's ability to access a portion of his Gear powers while donning his Gear-Cell Suppression Device. When activated, he gains a substantial boost in strength, speed, power, regeneration and durability. The power of his fire magic and special techniques are also increased dramatically. The drawback is that he cannot sustain this level of strength for an extended period of time because of the limiter he wears on his forehead. Throughout the Guilty Gear series (more prolifically, Guilty Gear 2: Overture and onwards), Sol's Dragon Install is steadily becoming closer to his natural Gear form due to the fact that his Gear-Cell suppression device is beginning to malfunction, which is attributed to his body and powers' continuous evolution and growth. In Overture, the Dragon Install features the greatest display of his Gear form to date, though it is noted that even in this state, he is still holding back and it wasn't his full transformation.
In Guilty Vastedge XT and Xrd -SIGN-, it appears that he has modified the limiter and is once again attempting to repress his power, though not to the same degree that he was able to in previous titles. His new Dragon Install seems to be connected to the Backyard, as the magic symbol associated with it appears on his sword and is featured on his jacket, that materializes as he uses the Install (although he can be seen wearing this jacket in his human form in Xrd's story mode). No official explanation on the connection between the Backyard and Sol's new Dragon Install has been given yet.
In gameplay, it's said to not often be very practical, as despite its massive increase in Sol's movement and attack speed as well as the extra absurd properties on his moves as more get added per game in the series, the moment in which Sol is vulnerable via him entering a brief state of his stunned animation allows the attack to easily be punishable in the open, as Sol will have to alleviate his powered-up assault sooner or later. Not to mention the timing for his cancels and general combos are vastly altered on timing due to the increased speed at which almost all of his moves come out and end alike, having less start-up time and ending lag (which makes his poking very hard not only to punish but to time just as well). But due to the time limit on this Overdrive, a DI'd Sol cannot afford to often stick to a patient playstyle, and for most players it is best to use this during combos, where Sol can find a way to let loose all-out on his opponent without needing to get punished if he tries to activate it during a neutral position. It also possesses a great deal with start-up invincibility as well compared to most Overdrives, but very rarely is this ever encouraged to be used as a reversal. Order-Sol's version in Slash and Accent Core powers up all of his moves to their Lv. 3 charge versions, much like in the very first game of the series, and has the same drawbacks. But Order-Sol's version can link into his Instant Kill, Sakkai, with good timing. Also, both Sol's have had a major drawback added on to Dragon Install ever since Slash; the mode will instantly end with a knockdown and Sol's resistance to being dizzied will drop.