So we can pick from
Decode - Dark = Ai
Encode - Light = Lightning
Excode - Wind = Windy
Powercode - Fire = Flame
Transcode - Earth = Earth
Shootingcode - Water = Aqua

Anyone else notice that each Code Talker represents a Ignis?

If you chose Decode
Having allies powers yourself up even more, but when critical moments happen, you may sacrifice one to save yourself. Are you willing to do just that?

If you chose Encode
You shall protect an ally once a day from the harsh reality of today, making yourself or your ally even stronger than before to overcome this.

If you chose Excode
Your main priority is to strengthen your allies and protect from from mental abuse along as your with them

If you chose Powercode 
Your willing to sacrifice anything, even your most precious allies just to win. No matter what the consequences are

If you chose Transcode
Whoever you trust grows stronger with yourself while both of you are together. You bring back an ally after realizing a horrid mistake, pleading that he/she forgive you.

If you chose Shootingcode
Your allies provide you strength to fight on, however you fighthonorably, when your opponent is weak, you weaken yourself to be on a even field so you're not seen as a coward who cannot fight on his/her own behalf

Hehe, random trivia. But in all honestly, favorite Code Talker from
Design
Effect
Name
Linkage requirements?

In all honestly, for me it's Excode, effect is pretty cool (yes all of then are but I just find I link summon Excode the most)

And yes I know I didn't include the original Code Talker. But that one doesn't really count..