1) No matter what build you entertain, your AA dmg is going to play a vital role in your output in team fight scenarios. This talent gives you incentive on 2 fronts to stay involved in team scenarios. Which you should always look to do when playing Varian as a tank.

4) Major power spike. Changes slow to stun on charge. Gives you a targetable stun every 6 seconds which cannot be overlooked.

7) Factor in what you are picking at level 10 when deciding which of the 2 sustain talents you want at 7. Because this is a tank build Varians AA speed gets nerfed at 10. Which means that the heal per attack mechanic does not have the same viability for this build the way it does on a dmg build. And the heal amount on victory rush is amazing. As is the cooldown reduction you receive for minions dying around you.

10) The effect and subtlety of this ability is incredible. The combination of the stun you gain at level 4 and the taunt you gain here means that you can remove a players ability to control their hero for 3 seconds. Which in most cases is long enough for your teammates to focus down your chose target. When done right whover you taunt dies as a result.

13) Banner that makes the entire team tankier as a whole. Which means they can stay in team fights long enough to take advantage of your cc.

16) Adds percentage based dmg to the stun you have every 6 seconds.

20) Adds healing buffs to your banner of choice while also cutting the cooldown of the banner by almost half of its amount.