If Void Seeker targets a unit that becomes illegal (e.g., removed by Retreat as a reaction), can you still draw a card?

Ruling: Yes, you can still draw a card. The spell must have a legal target to finalize, but once finalized, "do as much as you can" applies—you skip game actions involving illegal targets but perform all other game actions.

Sequence:

• The spell must have a legal target when it finalizes
• Once finalized, resolve the spell using "do as much as you can"
• Skip any game actions that involve the now-illegal target
• Perform all other game actions (like drawing a card)