This build is pretty default and will work in the majority of lobbies. Outside of the 3 optional swaps I've added below, there's plenty of items to consider. I'd say stuff like Draconic, Combat blink, resolute mantle all have the potential to fit into his builds, so stay flexible.
You can sell Alchemist Coat later on for Gem of Iso, the extra slows can get very annoying for a team with how much AoE you constantly have.
Whilst I would recommend a relic upgrade for most players, Ancile proc on Puch ult is VERY strong. You pretty much apply a team-wide silence in a fight with this combo, it's up there with Ancile + baron ult in terms of value/impact. Definitely an item that has a place in puch builds so keep it in mind.
Adds quite a lot of damage in exchange for CD/Mana. The extra HP of glads can feel nice as well.
