I noticed one big handicap for me and my team is so vulnerable to Colen and it kills almost all my team at one mana hit! minimum 2-3 kills at one shot and remain team is almost dead.
Team is Wu Kong, Rigard , Boldtusk, Little John, Grimm and all assended 3/60 Boldtusk and LJ 4/40
I really do not understand when I even could not fill one hero mana all opposite team players hit each turns. Come one little bit fair and justice developers!!!
You can try attacking with double blue color to kill him before he fires his special, for this task I use Grimm and Sonya.
You already have Rigard wich can counter Colen’s special pretty well but killing it with blue tiles is better. If you can’t reroll until you get better heroes to fight him.
I havent Sonya and opposite team mana refills faster than mine. I also seriously think it is uselss whatever hero card state their attack power or mana speed! I have no chance if game engine set me up to loose the raid…
When I were without 4 
heroes I were attacking with Valen and Graymane (vs lv 60 Colen or lower), the only important thing is to track your mana:
Fast = 8 mana
Medium = 10 mana
Slow = 12 mana
If you send a tile into a empty space it count twice. “Craft” dragons and gems, keep track of the mana you need and fire your specials.
If you can’t do it then reroll as I were rerolling on lv 70 Colen when I started the game.
Your options are:
Some great advice I read on these boards: Expect to lose about 1 in 5 of your encounters against teams of similar level to yours simply on bad tiles. Sometimes it happens and even if you have double blue, AND Rigard AND a blinding hero, you just can’t engineer a win. It happens. The only thing you can do is maximise your chances so that if you get a normal or better board you stand a decent chance.
Colen has probably the most powerful special among 4*, and your heroes (especially Grimm, Wu Kong and Little John) are all great heroes but not exactly tanks.
Thats why they get incinerate if you let him fire once.
At some point, all of us had some problems with centrals Colen, but you get through in no time 
I was thinking the same thing - to both your and @Little_Infinity’s point. You field a glass canon team - which means if you can get the specials and tiles right you should be able to wipe him out easy, but if you don’t and he fires, they will take an excessive amount of damage as their combined defense and health stat is much lower than your average 4* and way less than a tanky one who can at least absorb the first hit well, get a heal/cleanse from Rigard and act like Colen never even fired.
In fact Boldtusk and Rigard can not defend him as they must and balance of his fire and attack power is not fair or buggy. His mana speedly fills and fires always before me and kills WK, LJ / Grimm min two and remain team are so weak and killed by other team small strikes. What I mean once he fires then I am not having any chance to heal and strike back.
When you see colen’s mana almost filled up go on and fill rigard. First thing after he fires you use rigard and everything is fine. If rigard fills first, hold for a while and release after.
There’s also a great tactics against Colen I’ve read here on the forum but forgot the person to give credits
“Every time Colen fires his super, I run around screaming on fire and get on my knees praying the other team dies first”
