The Drive Blade is the favored weapon of the Imperial Class in Etrian Odyssey IV: Legends of the Titan. It is a heavy, 2-handed weapon with a powerful motor built into the blade and the ability to utilize cartridges to boost its damage output or allow for elemental strikes. Though the weapon itself cannot be used alongside other weapons, owing to its requiring two hands to wield, it is fully compatible with sword techniques used by the Landsknecht and Nightseeker classes, it does more damage than a conventional blade, and its unique ability to engage its drive motor can make it far more powerful than any conventional weapon has any right to be.
A few characters in Etrian IV explain its method of operation, in varying levels of detail (Wynn and some NPC Imperials in Tharsis being the most obvious), and some data on the weapon exists in the official artbooks.
The Drive Blade is a large, bulky sword that features a powerful internal motor, a slot for cartridges, a hilt with a motorcycle-like starter, and a trigger for actually engaging the cartridges. When employed conventionally, a Drive Blade shows none of its power, but in trained hands, this complicated weapon is capable of grievous damage.
To employ a Drive Blade, a trained user must engage its engine before swinging. The act of pulling the Drive Blade into position and revving up the motor takes time, and usually ensures that barring special circumstances, the Imperial will go last in a given round. When swung, the motor generates tremendous centrifugal force, brutally chopping through what's in the blade's way through sheer impact (Assault Drive). When engaged with a cartridge, the blade can be charged with energy (Flame/Freeze/Shock Drive), further increasing the damage of this terrifying weapon. As a drawback, the Drive Blade's motor generates tremendous waste heat, and after every such attack, must allow the blade to cool down between swings. The heat buildup is considerably worse if using a specialty cartridge with the attack. Some Imperials are masters of taking advantage of the overheated blade to improve their own damage output (Drive Mastery).
The gun-like cartridge mechanism allows the drive blade several options - it can be used with the motor for Drive attacks (Flame/Freeze/Shock Drive, Accel Drive), and it can be used without it to generate special attacks (Sharp Edge) or act as a heat sink (Heat Sink) and bring the blade's temperature within safe levels to be used again (Cool Edge). Rare rounds can be used to prep the blade to do additional damage (Charge Edge). The engine can also be optimized for repeated used (Ignition) and overclocked from Ignition state for incredible widespread damage (Overdrive).
- In the Sentinel graveyard (which is to the southwest of Sentinel village in the Golden Lair), a Sentinel NPC mentions one of the graves belonging to a human (later revealed (depending on the player's choice in the battle against Logre) to be Emperor Alfodr from the Cloudy Stronghold); he also refer's to the human's weapon (a Drive Blade) as "complex, nigh-unusable weaponry," referencing the dubiousness of the weapon's real-life practicality.