The egg doesn't effect tommy

The egg wants tommy dead

Niki and Jack are too much of disney villains to be able to kill tommy

Dream in jail

I suspect a betrayal

The egg affects tubbo, he hates it but eventually anyone who hates it comes to like it, example: corrupted!sam, red!skeppy

Also, in each season there was the betrayal line "it was never meant to be" that line was literally in every single season

What's more dramatic than having the right hand man (tm), the cute bee boi, tommy's own best friend, betray him for the second time and kill him while on the influence of the egg?

Or just my regular theory of the syndicate, puffy, tommy and dream teaming up against the egg with the help of revived wilbur and jschlatt (if they do get revived)