If I play against a heavy AD team or an AD top laner I love to rush ninja tabi, this item is great against AD top laners and especially good against auto attack based champions. The next item I like to build is iceborn gauntlet. It's passive compliments Gragas' offensive play style and its armor, cool down reduction, and mana work greatly to your benefit. The third item I buy is usually spirit visage, or any other magic resist item. I chose Spirit visage due to its passive generously contributing to the effectiveness of your passive. Your fourth and fifth items compliment each other greatly. Gargoyles stoneplate gives Lockett a larger shield due to your large max health. Lastly I build another magic resist item such as Abbysal mask due to its decent amount of magic resist and its passive being very good, if you have ability power dealing teammates. Another item you could go is adaptive helm, its passive is very beneficiary while facing somebody like Syndra or Lux.

Take Q first and on the first wave take the melee creeps first. While doing this align your Q to damage all 3 caster minions. Pop the Q once it turns purple and finish off the wave. After hitting level 2 take E and charge your opponent (unless it is a losing lane matchup) you will first use E and then auto, followed up by a Q. After this, take the occasional trade using W, then E, followed up by an auto attack, and finished it off with a Q. Play the rest of the lane like this and at about level 9-11 take rift herald. You can solo the rift herald by simply going to hit its eye when it opens up about every 6-9 seconds. During team fights try using E and then flashing to engage (use ult as you need to). If your team needs you to peel save your ultimate and dash to disengage assasins from your carry.