Level 100 Statistics (see level 5, 50, 100)
Wormadam is just another one of the many horribly outclassed Grass-types in UU. It has a decent base 105 Special Defense, but its Bug / Grass typing curses it with far too many weaknesses to wall anything effectively. It does possess a decent base 79 Special Attack stat, but many other Grass-types in UU (such as Venusaur) provide higher offensive power with fewer drawbacks. All in all, while Wormadam is usable, there are far better options.
This set is Wormadam's best attempt at damaging opposing Pokemon in UU. Despite being outclassed by many other Grass-types, Wormadam still possesses a few tricks of its own. For one, it flaunts a secondary Bug typing that provides it with a resistance to popular Fighting-type attacks, as well as decent special bulk to help it tank neutral attacks effectively. All of this, combined with Wormadam's ever-useful Grass typing that helps it massacre Milotic and other Water-types, makes it a decent if not preferable choice.
Leaf Storm is Wormadam's most powerful attack, capable of scoring OHKOs on many of the Water-types in UU, such as physically defensive Blastoise and Milotic. However, the Special Attack drop is extremely crippling to Wormadam. Psychic is a strong alternative against opponents resistant to Grass, such as Venusaur and Weezing. Signal Beam and Energy Ball provide reliable STAB attacks, forming the core of Wormadam's moveset. The choice of Hidden Power is a decision between being able to damage opposing Fire-types such as Arcanine or severely crippling Altaria while also hitting opposing Grass-types such as Leafeon for super effective damage.
Team Options & Additional Comments >>>
There aren't many other options Wormadam can utilize. It can change its Hidden Power type to Ground or Fire to hit Steel-types super effectively. However, the primary Steel-type of UU, Registeel, can easily shrug off even a super effective Hidden Power Ground or Hidden Power Fire. Shadow Ball is an option as a coverage move to hit Alakazam or Mismagius on the switch-in, making it a useful attack in the right situations. However, if either of these Pokemon get in safely they can KO or set up on Wormadam, making Shadow Ball situational at best. If Life Orb is Wormadam's item of choice, Toxic may be put over any move on Wormadam's moveset to cripple walls over long periods of time. However, Wormadam never stays alive long enough to outstall a wall and suffers greatly from giving up a coverage move.
Checks and Counters
As Wormadam will often be locked into a single attack by Choice Specs, almost any Pokemon can come in on a resisted attack and force Wormadam to switch out. However, several Pokemon can switch into almost all or all of its assaults. Two Pokemon that come to mind are Chansey and Registeel, each of which can switch into any of Wormadam's attacks and force it out or set up on it. Arcanine and Moltres also take very little damage from anything Wormadam can throw at them if it runs Hidden Power Ice over Hidden Power Rock. In addition, Wormadam suffers from a weakness to Stealth Rock without being immune to Spikes, meaning that several layers of entry hazards from Pokemon such as Omastar and Donphan can prove to be great boons in a fight against a Wormadam.