David is likely based off of an old French superstition that's focused on in the tone poem Danse Macabre (Camille Saint-Saens), which tells about how Death summons the dead from their graves every midnight on Halloween, to dance "their dance of death" for him while he played the violin. They dance until the cock crows at dawn, Death leaves and the dead return to their graves.
"Origin: ? A skeletal violinist. He plays crazed melodies on his enchanted violin. This music drives the listeners to dance the dance of death."
—Shin Megami Tensei A-Mode DDS dictionary
David is one of three rare and difficult bosses that can be found hidden in the game. If defeated, he has a slim chance of dropping the Stradivari, the most powerful Neutral-aligned weapon in the game.
David was introduced during the 2014 Halloween event where he was a rare boss in the Hacked Chip Kappa instance. As a reference to the rarity of fiend encounters in the original Shin Megami Tensei game, the event site stated "He has a higher than 1/256 chance to appear!" There, he spawned with a large number of Matadors who needed to be defeated in order to deal damage to him. Players were able to obtain him through an event quest where Pyro Jack wanted to recruit him for his band. He could be fused in a triple fusion of Matador, Turdak and Chatterskull.
"A violinist of inhuman power who appears as a skeleton. He travels around Europe with the gypsies and plays his enchanting violin that causes people to dance the dance of death."
—Shin Megami Tensei: Strange Journey compendium
David first appears in the EX Mission "Escape Plan," harassing members of the Strike Team who participated in the feint operation made for the protagonist to confront Master Mitra, and are now trapped due to being hemmed in by a multitude of demons. After killing the team's leader, David proceeded to stalk them through the sector, the music from his violin allowing the remaining strike team members to discern his location, but also unnerving them at the same time. When the protagonist helps the team find their way out, they find David stationed at the door they need to take to return to the Red Sprite, waiting for them. After defeating David, he becomes available for summoning using the Demonica's Demon Summoning Program with the Fiend Converter subapp.
David's dialogue and the ending of the EX Mission changes depending on the number of wrong doors the protagonist chooses. Behind every wrong door are demons that will ambush the team, which results in the death of one of the strike team members. If the protagonist manages to guide the team correctly, the entire team survives after David is defeated. If there were any casualties earlier due to the protagonist's wrong choices, after David is defeated, a pack of demons will ambush Dawson and Keema, who were the first two to rush out of the door leading back to the Red Sprite. The pair will then sacrifice themselves, pulling a grenade to take the high level demons into death with them.
"A violinist of inhuman power who appears as a skeleton. He travels around Europe with the Romani and plays his enchanting violin that causes people to dance the dance of death."
— Shin Megami Tensei IV compendium
David appears in the Challenge Quest, "Dance of the Dead," where his music has affected nearby villages with a fatal disease that turns one pitch black, leading to the quest to defeat him. He has brought forth five Calamity Hordes which dance to his tune, and appears to face Flynn after the last one's defeat. With his defeat, he is impressed that Flynn could evade his curse, warning him that it is not that easy to evade death, and that he will appear in another form eventually before saying farewell and dying.
David is unlocked for fusion in the Cathedral of Shadows after his defeat. He can be summoned through a special fusion of Chagrin, Apsaras and Naga once Flynn can control level 22 demons. David can teach Flynn the Mamudo, Pulinpa and Blight skills through his Demon Whisper.
David, along with all the other Fiends, is encountered in Twisted Tokyo. The first Fiend faced, David is encountered on B2F and drops the Stradavari from the second cycle onwards. He is fought at level 910 on cycle 9.
David's biggest problem-causers are his Dormina and his Haunting Rhapsody, which have a high chance of causing Sleep and Panic respectively, forcing Nanashi to lose turns in an already tight time limit per session. Haunting Rhapsody also reduces the entire party's battle stats, so immunity to Panic will not necessarily cause him to lose turns. Still, bringing demons immune to both Sleep and Panic, or with Null Mind, will make the battle a fair bit easier, as he would start to resort to his less effective Agidyne and Bufudyne attacks which also don't pierce any resistance unlike future Fiends. Fully debuffing him will cause him to use Dekunda.
One of the four new bosses included in the PSP Version of Shin Megami Tensei: Devil Summoner, David can only be fought after beating the game once. Its design is based on the Latter Human Type 2 form of Zeed in Soul Hackers.