Varian's talent tree is one of the best designed kits in the Nexus. He is versatile, powerful and quite fun to play, keeping his WoW Warrior feel intact and very familiar to those who liked the class in the game. When you are about to pick Varian in a draft process, you have to keep in mind that Varian is 100% dependent on your team and the opponents. He isn't like Thrall,Valla or LiMing that can function in a void, so in order not to screw things up, check what Varian brings to the table.

The Fury build, brings a Sonya like sustained melee assassin with great stick-to-target potential and probably the best 1v1 functionality in the game (expect Butcher w/ Lamb). In order for Fury build to work, you need opponents that you can hit a lot. He is not good if your opponents are mostly ranged or if the frontline is full of stuns and interrupts. REMEMBER, that the most important part of being viable as Varian, is being able to choose Warbringer without watering down your survivability. This means that you need to make the most out of Parry. Varian is a safe pick against opposing Auto attackers. Needless to say that the Fury build is the king of quickmatches, since the teams are uncoordinated and the Varian's 1v1 ability is much more useful;

The Arms (Colossus Smash) build needs a diving team behind it. At least one more of your teammates needs to be a diving hero, that can follow the Colossus Smash vulnerability in the brief 3 seconds it lasts. You try to delete someone very quickly by using all your cooldowns (R,AA,E,AA,Q,AA) and stay alive while you do that. If you have friends that can follow you in the burst process, Colossus Smash is golden. Note that your survivability is really bad, so you are not there for the sustained fight, but you want to get in quickly and get out with an advantage.

The Protection (Taunt) build, is in my humble opinion, the best build for Hero League, if the opposing team consists of many AA heroes. From all the tanks in the Nexus, Varian maybe the most linear one, but he is also effectively, the only one that can launch a 2,5 (approx) full CC on a hero with Warbringer and Taunt. Again, the trick to success is to avoid Shield Wall on tier 2, and get Warbringer for the increased peel/chase potential. At level 16 he gets good utility through Mortal Strike/Juggernaut/Shattering throw, making him a good asset for anything that the opposing team throws at you. Mortal Strike to help your team burst down someone easier, Shattering against Zarya or Juggernaut against big frontliners to help your team soften the target. In general the protection build is boring but effective, and you need to assume the role of the 'silent hero' that will get the dirty job done and let his allies shine. Protect them through banners, peels and body blocks and taunt the focused target keeping them busy and away of your squishies.

Try to see Varian as a very bad early game hero. Play timidly, don't overextend, and try to get the level 1 quest done. Participate on your team rotations, hit heroes, gather globes...or just hit Maws. The name of the game is safety up to level 10. When you assume a role, Varian needs to play accordingly. If you go Fury, you need to search for the 1v1. Stalk, help on gangs and flank the opposing team. If you go Colossus Smash, stay with your team, ping a target and go for the kill. CS is on a low cooldown so you are not wasting it in attempts to get someone down. Usually the Cooldown you put on someone's death is much bigger than your CS cooldown.

If you go protection, you assume the role of a damage sponge with a lock-down potential. Do exactly that. Get in the face of people, absorb damage and taunt squishies to attack you that would normally avoid you. REMEMBER, Varian tank is at its finest if you don't require Shield Wall to boost your life expectancy, allowing him to get Warbringer's stun.

Fury build, along with its great sustain has also the added advantage of having amazing PvE potential. You can solo any mercenary camp, including bosses. If you notify your team that you are going to solo a boss, make sure that they keep the opponents busy so that the enemies don't spot you. You need almost a minute at level 10, to solo a boss given you went Fury with Second wind.

There are two ways for Varian to get life back. Both reside on tier 3 (level 7 talents) and work entirely different.

Second Wind is obviously the best way to get high in HP, provided you keep hitting your auto attacks and keep hitting your target. Apparently it loves Fury's attack speed and it can get Varian up to full life just by clearing a wave of minions with AAs, or hitting a hero for some seconds.

Victory Rush is a different beast. It is a burst heal that procs off a single attack per 60 seconds. This means that it loves slow auto attack builds and due to the fact that the CD is reduced per minion death near you, it's better to be used on maps that consist of in-lane fights and lots of minion kills (Dragon Shire, Tomb of the Spider Queen, Infernal Shrines since Shrines are near lanes, Cursed Hollow's pushing phase etc.) In general pick Victory Rush on Arms build OR Protection in case Parry isn't doing much.

In general if you run as a tank, you get much more from the increased Parry duration and CD reduction, unless you are not facing an AA team. If your opponents are spell based and for some reason you want to play Varian, probably a combination of Shield Wall/Victory Rush will get you more value.

If you want to have QM fun, get Fury and ride the damage and PvE potential. If you have a team that can dive with you, get Arms and get an easy advantage. If you find yourself against an AA based team and you want a front liner with an unmissable 2,5 sec lock-down, got Protection.

Play according to the opponents. Sometimes even Fury is much tankier than Protection against the right opponents.

Play safely up until you get your heroic and always stay close to your team, or keep an eye on enemy movement in order to isolate and kill off-position assassins/specialists as Fury or Arms. Get a grip of your role and play accordingly, Varian is not a top tier pick but he is fitting in many teams and is appropriate against many teams. Right now (as of end December 2016 Ragnaros' Patch) I would place Varian as a tier 2 hero that is viable but not always fitting the bill. He is very effective against AA teams but weak against spell centered opponents, and needless to say that with his Shattering throw on level 16, he is the worst nightmare for Zarya who is a top-pick lately.

Enjoy!