Zeri gains Move Speed whenever she receives a shield.
Zeri gains Move Speed whenever she receives a shield. When she damages an enemy shield she absorbs its energy, shielding herself.
Gotta go fast. Riot designers really envision Zeri as an extremely mobile champion, which probably captures her biggest advantage as a marksman. She can chase down kills and sneak away if under threat. She’ll be a great kiter too, so this adds dimension to how teamfights play out in the mid and late-game. Her passive alone already makes her seem quite a bit overtuned. Gaining movespeed whenever you have a shield means she’ll pair up great with Enchanter supports who also give movespeed like Karma or Yuumi, or even with an Orianna mid. If those buffs stack, you’ll have one lightning-fast marksman for sure.
Besides that, the fact that Zeri can gain a shield for herself, by damaging an enemy shield, also means she can activate the speed buff herself quite often. This further gives her an advantage when trying to chase down an opponent, so not only do you get to break the enemy’s defenses but you even get a speed boost to catch up to them. It might also mean Zeri could be a good counter against teams that do use Enchanter supports. Breaking the enemy’s shield could help Zeri escape the opposing ADC boosted by the support’s shield.