Decode's a good generic link, and Transcode is really good, and it seems as though it's coming at launch. But as for Accesscode, probably best to build the rest of the game before adding such a board breaking card.
I wouldn't be surprised if Access is treated in a similar manner as Shooting Star Dragon where it's only available via a Skill that pretty much locks you into a Code Talker deck.
Took a bit of time from the updated Yusei starting Skill to getting the Stardust Structure and Prismatic SSD so it might be a few months before we do, if that's what they consider the Code Talkers ultra form to be.
Destroys a card by banishing a link monster from ur field/gy and it's not once per turn but you cannot banish links with same attribute. He also gains 1k attack per link rating of a material used to summom him so if you use Heatleo, that's additional 3k giving you a total of 5k something. If you used update jammer to summom him too, accesscode can attack twice.