The link I sent earlier is worth reading. It addresses some of the points that have been made re: eye color and the mindflayer in the goblin camp.
There's a contradiction in the mind flayer dialogues. One option makes it clear that this wasn't the mindflayer who abducted you - it's clothes are plainer and features are different - another makes it clear that it IS the mindflayer who abducted you. This should be cleaned up.
On the eyes - yes the emperor has purple eyes. But also note that Lae'zel looks different, different facial markings, different war paint, fuller face, different armor. But it's clearly her.
Also note that orange eyes are used as sign of illthid domination in the cinematics that the emperor shows us. So it could mean that he was being dominated while tadpoling Tav.
But I'm going for option 1. The emperor knew what he was doing, he tadpoled us and the differences in appearance are due to the age of the cinnematic. Larian just tweaked his design.
