This just happened to me. I defeated someone who was utilizing a mono Strength/Green. I am always very satisifed when it happens -- so I'll share what happened. I think it might be the first time I was successful using a particular deck.
My deck name was called: "Chained Attacks with 6 Green Blocks and 4 Red Blocks" (obviously that's me writing out my nomenclature). The concept is to maximize use of chained attacks, "Samurai Slash", "Raptor Rush", and "Slice N Dice Furyfest" are prominant cards. Looking at it more I also have many anti-keeper cards and fewer chains than I expected to see. The deck is predominately Orange/Speed, Blue/Elemental, Red/Animal factors. I only had 6 Green/Strength cards.
So myself and random opponent pass at the low levels (simply because I'm building a hand for future chaining) on a number of turns; we start attacking when the power hits Level 3 (we had 8-9 cards in our hand at one point). I was getting suspicious after the first couple of attacks he had, but after I saw 10 Green/Strength cards I was certain he was using a mono-deck. So I knew 2 things: Don't block any of his lower power attacks, and try to block the attacks that will certainly take a block from the deck. Additionally, feel free to just attack with everything else in my hand. Typical decks I build will have 7 of each factor -- which is why I name them to remind me which factors I'm short.
Fortunately, the ending was quite spectacular. I had managed to get two copies of
Stegosaurus Spines in play.
When the Power Level turned 8,
Raptor Rush fell into my hand (it actually may have been 1 turn before 'cause I was hoping the coin would increase the power). So I pulled off the combo here.
Even though he blocked
Edge of Danger, it still activated the keepers.
And then I managed to mortally wound him using
Turnabout.
I think he strategically assumed it was going to get blocked earlier, but it ended up doing 10+ damage and the power level didn't even come near Level 13. He must've thought he had to save that card to get rid of my keepers.
So, fun game: if you are taking on mono decks remember -- you need to play the mono-factor back to have a good chance of winning. Also, choose how you use your blocks wisely, *and* it does take some luck.
Incidentally this player came back and beat me with an Elektra-Daredevil combination (Orange/Speed, Red/Animal, Purple/Mystical?) type of deck. I was using a deck that was low on Orange/Speed blocks, but made it nearly to the end.