After playing Volibear for a while I wasn't content with any builds that I had found so I started expermenting with builds and items and found one of the most effective builds I've seen in 3v3.
This build is still a work in progress and will be updating as I learn more.

If you like the guide or find it usefull, please rate it and leave a comment :)

(Bear with me because this is my first build, so don't expect anythinng fancy. This is just the nitty gritty guide to wrecking with the great armored bear.)

Chosen of the Storm (Passive)
Volibear heals rapidly for a few seconds when his health drops to a critical level.

This passive regenerates 30% of your max health over a short period of time. Great for baiting enemies because you look near death, or just sustained laning. Beware of summoner skills such as Ignite.

Rolling Thunder
speed increases when chasing enemy champions. The first enemy he attacks is thrown backwards over Volibear.
Volibear drops to all fours to hunt his enemies, gaining 15% Movement Speed for 4 seconds. This bonus increases to 45% Movement Speed while moving toward enemy champions.

Volibear's next attack during this time deals an additional 30/60/90/120/150 physical damage and flings the target behind him.

This skill is perfect for flipping enemies back into range of a team mate or turret, great for kiting, and paired with Ghost provides a nasty speed boost.

Frenzy
Volibear's repeated attacks grant him additional Attack Speed. Once Volibear has repeatedly attacked three times, he can perform a vicious bite on his target which deals increased damage based on the target's missing health.
Passive: Volibear gains 8/11/14/17/20% Attack Speed with each attack. Stacks up to 3 times.

Active: When Volibear has 3 stacks of Frenzy, he can bite an enemy to deal 80/125/170/215/260 (+  [15% of bonus Health]) physical damage, increased by 1% for each 1% health the target is missing.

Use this to do burst damage to finish of an enemy.

Majestic Roar
Volibear lets out a powerful roar that damages and slows enemies. Minions and monsters are feared as well.
Volibear deals 60/105/150/195/240 (+0.6) magic damage to nearby enemies and slow them by 30/35/40/45/50% for 3 seconds.

Minions and monsters are feared as well.

This skill is the bread and butter of this build. Also I feel it is severely underrated. With the burst speed of Volibear, this stun is crucial for keeping enemies in range and preventing them from getting away.

Thunder Claws
Volibear channels the power of the storm causing his attacks to blast his targets with lightning that bounces to other nearby enemies.
Volibear channels the storm, causing all basic attacks for 12 seconds to deal 75/115/155 (+0.3) magic damage, which chains to 4 nearby enemies.

Finally the Ulti, a great skill for mowing down minions, killing the dragon, or burning down turrets. Also can be used as a ranged attack to hit other Champions with Chain Lightening.

The route I chose to go in runes requires little explanation. Stack Alacrity in all slots to maximize attack speed and to gain the full potential Volibears high attack power.

After a lot of deliberating and testing, I've found that these skills paired with Volibears abilities make him damn near impossible to catch, and even harder to get away from.

For the first spell I pick Exhaust, slowing them down, and reducing their armor will greatly help in securing kills early on.

Secondly, Ghost for your all purpose kiting, or closing the gap between a Champ before they get away.

The item shown earlier are your core set. The purchase order is for an ideal situation, but can be adjusted as need be. The main focus of this build though is making sure you have Warmongs before lvl 10. This will set you up to be much stronger than other champs for the rest of the game.

Next comes the Frozen Mallet, the health plus reducing movement speed is crucial paired with your stun.

Then logically to optimize Volibears already substantial health comes Atma's Impaler.

Topping the build off end game could be a number of things but personally my favorite is The Bloodthirster then selling your boots to make space for Sunfire Cape.

Keep in mind this build is still in the R and D stages.
Some important things to note this build is pretty squishy pre lvl 10 (or Pre warmongs) So keep that in mind but otherwise you should be sitting around 275 attack damage with close to 4,000 health.
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