If you meant you want gaia not to be seen by other players, try this, but then also the owner can't see it. He'll only see the unit, without LOS.
Try to use the effect "Modify protounit", select Titan Gaia, select LOS and set -20 as delta.
Then place your gaia where you want. If you have nottud's editor superpack, you can also make her smaller.
AoMH retired Scenario designer
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