Abilities\Spells\Human\MassTeleport\MassTeleportTo.mdl
Abilities\Spells\Human\MassTeleport\MassTeleportCaster.mdl
Abilities\Spells\Human\MassTeleport\MassTeleportTarget.mdl
You can get these by going into the Object Editor, looking up the Mass Teleport ability for the Archmage, click Art- Area Effect then click "Edit model" & at the bottom you'll see "Custom" which displays the path.
You can override that path but any teleport abilities (which use the same model path) will also show the new model.
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