And with their ability announced and finetuned a bit I have gotten a ref from the wonderful  DragoShift17
While there isn't an icon in the trading card game for all the types I'll still have them effected by those types regardless. Now as for the ability itself I changed it up a bit to where it will, upon changing belly icons, change both the main type(water is the replaced type if no other belly symbol was present at the time) and the signature move of that type(so for water type it would be water shuriken as thats the unique move for greninja) to fit the current type of Echo with unique naming and all, though I'll save naming all of them for later whenever the symbol of that type becomes present or if someone asks.

As for Echo themself they're an explorer thats part of the expedition society, usually out on their own to both deal with outlaws and uncover more of the global map in the society base. They have passed by Lynus once or twice while in the grass continent however. Lynus due to their nature simply ignored them most of the time as they weren't the best with conversation, that and Lynus didn't like being called cute, which Echo often does to those they think deserve to be called as such. Echo unlike Lynus however is skilled in hand to hand combat but any ranged opposition would most likely be able to snipe him before he could get too close.