Hi! I have been collecting challenge coins and I would like some advice as to where to use them. I have all the 4* so I’m mainly interested in 5* that could improve my roster. My initial though is festival for the new costumes, but I’m not sure.
My challenge heroes are:
Festival: lady of the lake, guardian panther, c guardian kong, white rabbit, rumplestikin, the hatter, lady locke.
Gargoyles: peñolite
Clash of knights: ludwig, wolfgang, rayne
Circus: faline, bobo, theobald
Others: karnov
It seems like you already have a good roster of challenge heroes here. Of course, these are just my opinions and will also be subject to how many coins/pulls you have available to you!
Based only on your list, I would pull at the upcoming Challenge Festival until you get Black Knight, then stop, and hold your coins until the next event with the bards / circus / villains. There’s a couple of the “A+” heroes from circus that you’re missing, plus, villains are getting a boost. If you manage to get Panther or Rumple, then that’s great! but you’re missing a taunter here (assuming you don’t have either Krampus or Kara of course).
Realistically, you’re probably better off pulling for costumes where they’re featured. (LotL / WR - should be featured together)
Starfall Circus, Slayers and Vliians will go into Challenge Festival II along with brand new Bard heroes.
oh really? So I don’t have to bother about pulling in the circus, slayers and Villains.
As taunter heroes I already have ludwig and kara, that’s the reason why in soul exchange I went for LoTL instead of Black Knight. However, I’ll try to get some festival heroes with or without costumes. If the pulls go well, then I will use the other coins gems in gargoyles or clash of knights or maybe in estigia? one of the upcoming events…
Here’s a link for you 
I don’t know that they’re planning on releasing a new currency for it, but it could be a better time!
It will run on the same challenge event coins like the other Challenge Festival, and there will be no chance to pull Season 1 heroes in that portal either.
I am planning to use all of my challenge event coins here as I have only 3 heroes in total from these.
I’m planning on using mine in challenge festival II too.
same, bigger pool of heroes I don’t have yet
I think that a lot of people are waiting for CFII. From this portal I have Candy, DAndre and Whacker only, so there are many new heroes that I may get. I’m curious why they added new Bard heroes to it, but didn’t include Gorgoyles. 
I’d advise you to pull at the upcoming Challenge Festival.
Guardian Panther costume will be a beast.
Fixed 20 charactersssss
I already have the normal one +20 and LB 
so yes, panther, black knight, rumple… or any other would be a great addition to my roster.