Concerns of The Deep? I'm Punchin'

Buy left to right
If you lower the Bullet Resistance of the enemy, it means you'll deal more Melee Damage to them! If you feel like you'll parry a lot, get Rebuttal in the Parrying section! Upon acquiring Express Shot, use your Alt-Fire (RMB) to deal big damage! Just remember to wait 3s between shots to get its effect! Use it after a Heavy Melee!

Buy one of those items to remain in lane and not miss out on souls! Sell the item you picked later
Melee Lifesteal works with Puddle Punch (3)
Extra Regen is the most passive option
Resto Locket will allow you to regain 2 stamina upon use!

Buy left to right
Use a mix of Melee, Alt-Fire and Puddle Punch (3) to deal damage, heal and debuff your enemies! If you don't have a flex slot, skip Phantom Strike and buy it as soon as you get a slot.

If you are confident in your parries, then these will help you dish out more damage and increase your survivability by a considerable amount.

You can buy left to right, or pick whatever you deem necessary after getting Transcendent Cooldown
Don't forget to get an Active as it'll allow you to deal with many different threats by either gaining resistances, movement, CC, healing and more!

If you find yourself dying easily or taking too much damage, consider one (or more) of those items! Since the rework, Barriers work with Resistances.

Those actives are extremely powerful items to gain the edge against the enemy
If you frontline a lot, Focus Lens is useful if enemies tend to escape before you finish them off
Do not buy Return Fire if you have Juggernaut
Recommendation: Return Fire or Scourge.

If you feel like that Crippling Headshot isn't enough to reduce the enemy's healing consider one of those! Healbane is the cheapest and can be triggered by dealing Spirit Damage! Recommendation: Healbane.

These items will help you have a better time against specific enemies or simply allow you to modify your gameplay to something that fits you more
Keep in mind that these items are NOT part of the build
Decay, Silence Wave, Knockdown and Curse are powerful actives that can be bought to counter specific heroes.