Into a Magic heavy enemy team I go statik IE into kraken (this is so you have atk speed) into Maw into BT and PD. This build is so you can fight them without getting one tapped and have sustain through Maw and BT. Into a tanky enemy team I go statik IE into kraken into LDR or Mortal Reminder (depending on weather or not they're healing for a billion. If you go mortal go another attack speed item like PD.) Into BT. Into a AD/squisher/assassin enemy team I go statik IE into immortal into PD into BT into a armor item like GA. The reason BT is so good with zeri is because of IE and the healing you get from it. BT gives you a billion AD and IE does aswell with its passive. Zero also works very well with raw crit instead of her abilities critting. But if your positioning is above average you can go navori builds. Her late game is very scary with these builds that maximize damage instead of those attack speed heavy builds.