Smoking Lightning's gear is reminiscent of a stereotypical ninja's attire. Like the other leaders of Hamelin, he wears a red kerchief over his nose and mouth. His weapon seems to be a dagger or short sword.
Before the Catastrophe
In the old world, he was a stingy swindler working in another MMO company who was involved in illicit [Trading in-game items/money for real-world goods/money]. While scouting out in Elder Tale, he ended up getting involved in the Catastrophe.
At the start of the Catastrophe, he planned on making bank off buying beginner players' EXP Pots, and then selling them for a higher price. His guildmates, however, convinced him that beginner players wouldn't be able to fight back, so they could instead trap them and use them as a source of infinite money. Though he thought to himself that this was a dangerous line to cross, he ended up swept up by the group's fervor nonetheless and consented to the plan.
Round Table Alliance arc
In the anime, Smoking Lightning is the one who notices the kids attempting to escape. Touya uses Lanius Capture on him, forcing him to keep silent for 15 seconds. Once those 15 seconds were up, however, he yells out a curse, prompting several other Hamelin members, Shredder included, to come out of their rooms to see what the commotion is about.
After finding that their access to the Guild Hall has been blocked off, Smoking Lightning is among those that are implied to have committed suicide in order to respawn at the Cathedral. With Akiba now inhospitable to them, he leaves with the former guild's remaining members.