If you think its hard to imagine the humanoid thing. u can use LOL (MOBA Game) Project skin, any mecha thing u like as reference.

And use Gundam, Zoids, or Transformer as its basic for the automaton. use u like.

but it didn't look like Evangelion so don't use it u gonna find it hard to use them. Some of my friend find hard to imagine the characther cause of it.

and that all

P.S. What i and u imagine maybe different but its up to you as long as u enjoy it and its mecha (it should be).

thanks for your support and have a nice day