Great fun (in diamond/champ) at low mana, is Tank, Ant Miners, and Flame Monkey.
So many times, they get through my tank, then struggle to punch through Ant Miner's armour, against Flame Monkey's repair. Throw in a serpentine spy somewhere, and all those opportunity kills add to Ant miner's health (through scavenge), so even if there are a few low damage, magic support enemies left, they struggle to chip away at Ant Miner's health.
It's been great for rentals. Particularly max cards. I'm normally glad to see 13K DEC/day at EOS. I'm over 16K right now with 6 days left.
I get screwed over by this often and I don't have a serpentine soldier or a spy - my Fire is lame! :D
The rental values are up a lot, which is great, but I also have to rent a lot to compete and there is hardly anything on the market available.