Future blue armor mage ideas?

Due to IS chimera ideias that DON T exist in FE series, its not posible to say, only especulation.

They can bring some ideias for the April Spring or June Bride events, that didnt included new classes of moviment with tomes or bows

Hard to tell, really. Arvis is already established as a red mage despite being the first armored one in his home game(granted that's when you control Seliph, the infantry one we have is when you control Sigurd) and Tharja blew that out of the window since her reclass option in Awakening is the Knight class which justifies her being chosen.

Not many options remain apart from delving into support possibilities in both Awakening and Fates or the convoluted reclassing with the Villager's Fork from Echoes.

If we're talking bulk, I can see Canas from Blazing Sword might work and he has the Anima affinity.

Well, if you compare the other two armors and see what similarities they share, we can see a pattern. First, its will probably be from a seasonal banner and both units were already mages in the game. Henry didn't keep his color so what color the mage is doesn't matter. Based on that I could see a couple possibilities, Bridal Sonia,Bridal Celica Easter Boey, summer odin. There really is no telling who it might be or from what game it can be from. I hope they do a husband banner this year to balance out the brides and it could be like Tomato Groom Leo. I would whale for that and maybe they could actually make him useable.

As the Thani s effect explain, reduce damage by 30% from cavalry and armor with tomes, bows and DAGGERS.... we dont even have daggers users on horses neither using armors...

I don’t see them going back to Shadows of Valentia any time soon because they’ve released so many of the characters, but Kliff would be a good candidate. He is pretty tanky and can do well as a mage or Knight.