In the current Planechasing PW Fblthp event, Fblthp was casting red cards.
And a green one! (Steel Leaf Champion)
However, since it’s a PvE Event Deck the usual color limits don’t really apply. Several of the fights in the Avacyn’s Madness PvE event cast cards not in their colors either.
Its probably not a bug, just very very confusing
I thought I was going crazy when he dropped a ball lightning.
Some PvE encounters use cards outside their primary color(s). I’m pretty sure this is intended when looking at what his deck is trying to do (use cards that abuse mana bonuses).
Hello guys,
This is as intended.
Only Fblthp is able to cast cards from different colors.
@Oktagon_Support if it’s working as intended why then is it only the ai has this intended ability and not us regular folk.
I mean, technically its not only Fibbles. A lot of the Avacyn’s Madness opponents also cast cards of different colors.
Its just a PvE thing that’s super confusing, that’s all. Of all the things wrong with the game I don’t think this is so serious.
The idea for Fblthp was that he would be able to use any card and these cards would be representations of the creatures and spells from the plans he visited. Not necessarily cards he knows how to cast/play.
This is a pretty cool tweak to that event (of which I hope to try before he disappears).
I’m glad they changed him up.
Great I do have him and have never played with him being he’s mono colored blue 
The “idea” I just mentioned is about the Fblthp PW used by AI during the Planeschasing event. It doesn’t apply to the PW you guys have.
Sorry about the misunderstanding. 