"exile until ~ leaves the battlefield" triggers too late

-- The situation

[[Rampaging Baloths]] exiled under [[Glorious Protector]]. I cast [[The Great Aurora]].

-- What happens

The Aurora resolves completely, then xmages shows a Glorious Protector trigger, puts the Baloths on the battlefield, then everything else resolves : the Baloths arrives after the Aurora has put lands on the battlefield.

-- What should happen

The cards exiled with Protector should come back as soon as it leaves, even if it's mid-resolution : the Baloths should be on the battlefield when the Aurora puts lands there, which means it should see them and trigger.

Start by reproducing the Glorious Protector and The Great Aurora scenario, then trace how the exile-until-leaves effect is handled during spell resolution. Done means the exiled Rampaging Baloths returns immediately when Glorious Protector leaves, before The Great Aurora puts lands onto the battlefield, and its trigger can see those lands.

Written by the indexing model from the issue text.