That's what i want too, the colloseum upgraded as fast as possible, because i do want the royal naga...
I like challange, but the goal We've got you Covered! triggers after you upgrade the Colosseum to Level 6 is boring, it will take days. i love smaller steps with a little challenge.
OH wouldn't it be fun if we could send a crest as a present.... Or a trap or a energy-box of 3 energies :-)