Hi!! I'm space girI, and I love Urgot! At the time of writing this I'm M7 with almost 100k Mastery on the executioner.

To put it simply: He's fun! You've got it all! A slow, a gap closer + stun, a ranged execute that fears, even friggin shotgun legs! He's really excellent mid to late game, and even early game in most matchups due to the sheer burst strength his passive provides.

Pros:
-Can 1v1 most champs if passive is up
-Ranged execute with fear
-Annoys the enemy team
-Can handle ganks
-Shotguns for legs!!

Cons:
-If you fall behind, you fall behind.
-Can be weak before powerspikes

Echoing Flames
This is your main source of damage. Each of your legs has a shotgun, with a cooldown on it, independent of the others. When farming, especially in early game, try to only proc one or two legs to farm, to leave the rest open to hurt the enemy laner.

Corrosive Charge This slows the enemy and does damage, pretty basic.

Purge What makes Urgot well, Urgot. Auto attacks 3 times a second the nearest enemy, or one that's marked for purging. This is done by damaging them with Corrosive Charge, Disdain, or Fear Beyond Death. Decreases your MS, but gives you slow resistance. The AA's apply on hits, but at 50% effectiveness. For instance, Blade of the Ruined King will proc for 4% on each AA.

Disdain I think this is Urgot's most fun ability. If you land it at level 2 with Purge and a couple Echoing Flames procs available, you win most duels if you can proc all the passive shots. Used as a gap closer, that stuns, gives you a shield, puts them behind you, and stuns them. The stun lets you hit your Q and your R for free. If they're near your tower, you can E them to put them behind you and get them to take a tower shot. You can also Flash during the windup. Can also be used as an escape ability.

Fear Beyond Death In my opinion, this is the most fun finishing ability in the game. Pretty standard, is a skillshot that does a little damage and lasts 4 seconds. Slows up to 75% based on how low they are. If they go below 25% during the 4 seconds, you can re-cast to reel them in, suppressing them, and execute. If you hit the execute, nearby enemies are feared and slowed. If used in teamfights and you get the fear, you will probably win that teamfight. A tip, if you re cast right after hitting the skillshot, it will auto-reel in the enemy as soon as they hit 25%.

The usual combo is E > AA > Q > W (if not toggled) > R > spin around them to proc passive.

If they're out of range of E you can start with Q instead due to the slow.