In order to register an ATA ID you'll need to do so through a mobile device. If you don't have access to one to setup the ATA ID you can either link through Facebook or send an email to support@athinkingape.com where they will manually verify and link your account.
How difficult can it be? Log in to PC KAW with your Mochi game ID. Once you are in your account on PC, at the top it gives an option called 'Link Account'. Click on that and link to ATA and/or FaceBook with an email ID and set a password. Now unless you cannot do that, then you email ATA with your user name, game name (kaw), mochi details and they do it manually. I do not see any reason to be worried and ATA has nothing to do with Mochi's decision to shut down. Do the xfer while you can or there nay be no hope later on, the more you delay it.
FYI: When writing into support, please include your 'kingdom' name (that appears in game), not your mochi account log in. You can also quickly verify your account by leaving in game feedback from the account itself. If you don't get transferred before mochi is down, we can still manually verify your account and link you to an ATA ID. Just write into support.
We've updated the guide on linking to ATA ID/Facebook on the first page. You can now register an ATA ID from the Mochi Games version of Kingdoms at War directly.
Thank you developers. Sincerely. I refused to install KaW on my phone so that it won't affect my work, and was prepared to let AppleSeeds die off. Being able to register an ATA ID is therefore a life-line. Thanks once again.