Team 1

Keeps: Shorekeeper stays in the team, so you keep his Spectro healing and team-damage buff, and Jingran keeps his third slot untouched.

Costs: Iuno's own descriptor is "Aero healer that buffs Heavy Attack": a direct match for Jingran's kit, which is built around Heavy Attack DMG. Lupa's descriptor is "Fusion Sub DPS that buffs Basic Attack" instead. The swap trades a Heavy-Attack-matched buffer for one that buffs a different attack type Jingran doesn't lean on, plus you lose Iuno's own Aero damage contribution and healing.

Rotation: Jingran's own Shield (and everything on his that reads it: his Echo set, both weapon options, Ghost Shroud) doesn't depend on this slot either way, since it comes from his own kit while he's attacking. What does change is Iuno's own Lunar Cycle mechanic, which Lupa doesn't have; the third-slot rotation itself plays differently, but no tested comparison exists here yet for exactly how much that affects Jingran's own damage window.

Energy Regen: Not verified on this site.

Requires: No specific sequence or weapon requirement is documented for Lupa in this slot.

Don't swap if: If you're relying on Iuno's Heavy Attack buff to carry a meaningful share of Jingran's damage, don't assume Lupa replaces that value one-for-one. It buffs a different attack type on Jingran's kit.