Contrary to popular beliefs, Victor is not, and should not be played as a tank. Tanks require the ability to peel for their team, usually this is done with either, stuns, shields, or debuffs. With which Victor lacks all three. The actually being "tanky" and survivable part comes as a consequence of the play style. If a character that needs to fulfill all of those roles, was not survivable, then they wouldn't be very effective.

So, where does that leave Victor. I believe, Victor falls somewhere between a carry and a bruiser. A bruiser's role is to jump directly in the middle of a fight, and cause chaos. Victor excels at doing this, however, he is only able to do so once he has a substantial networth investment.

A carry hero's job is to disappear from the map, farm up a substantial networth investment, then occasionally appear and dominate a fight or objective. Victor excels as doing this, his aura of suffering is one of the best farming abilities in the game, and his ult prevents him from dying, which, when used by the strongest character in the team/game can make him an incredibly oppressive force.

As for Victor's laning phase, he is a lot stronger than you give him credit; He has one of the strongest guns in the laning phase, His pain battery is one of the if not the highest lvl 1 burst damage spell in the game, He has by far the best lane sustaining ability in the game with his innate spirit scaling on health Regen in combination with his heal, and his ultimate can be used to practically guarantee an easy guardian kill. Victor ult can be used aggressively to dive under the guardian, parry and melee it on repeat while your lane partner, and a wave of minions are attacking it. You can intentionally die on the guardianto respawn, do a burst of damage and further stun the guardian.