Shelgon is a rather overlooked Pokemon in UU, mainly due to his NFE status. However, one who looks past such a label will notice quite a few reasons to use him. With the strongest Outrage in the UU metagame, good physical Defense, and a good boosting move in Dragon Dance, Shelgon can sweep unprepared teams.
However, Shelgon is not without downsides. His Speed and Special Defense are extremely poor. While he can boost his Speed with Dragon Dance, he will still be outsped by faster attackers like Mismagius and Alakazam, who are extremely common in the UU tier. His poor Special Defense means that you must go out of your way to compensate in order for Shelgon to be used effectively. Shelgon needs to be well-supported in a team or not used at all.
Boasting the strongest Outrage in UU, Shelgon can easily poke gaping holes into the opposition's team after a Dragon Dance. The idea is simple: Dragon Dance up whenever you get the chance and start attacking. Outrage is for pure power, while Brick Break is Shelgon's strongest option against the Steel-types in UU who resist Outrage. Dragon Claw is mainly a filler move, but it allows Shelgon to dish out damage without having to lock himself into Outrage and potentially getting revenge killed.Team Options & Additional Comments >>>
A Choice Band set with attacks like Crunch, Rock Slide, and Fire Fang can be used, but is inadvisable due to Shelgon's terrible Speed and Special Defense. On the topic of Shelgon's other attacks, while they are available to Shelgon, it is best to stick to the moves given, as the rest of the attacks lack power and do not provide much additional coverage. Shelgon also has a wonderful special movepool, but his lackluster Special Attack does let him down. However, one may use a Choice Specs Shelgon lure in physical walls like Steelix or Slowbro and 2HKO them with Fire Blast or Draco Meteor. Iron Defense is also an option, but would generally be useless because Shelgon would be forced out by special attacks anyway.
Shelgon can also go on a defensive route by utilizing a set with Wish, Protect, and Roar to wall physical threats like Aggron and Rhyperior. However, lack of Attack investment means that he is difficult to threaten said physical threats in any way, meaning Shelgon will lose eventually. Similarly, Shelgon can also run a RestTalk set, but again, lack of the Attack investment means he is not going to win against many physical threats either.
Checks and Counters
Steelix and Registeel are easily the best counters to Shelgon, only fearing a boosted Brick Break when they drop to around 60% health. Steelix can easily force Shelgon out with Roar, and Registeel can use Thunder Wave to cripple him.
Generally, the easiest way to remove Shelgon is by preying on his horrible Speed and attacking him with a powerful special attack. Anything faster than base 100 Speed with a powerful special attack that hits for neutral or super effective damage can either force Shelgon out or just KO him if he's locked into Outrage.