Xanarcah
S Class Trainer
I saw the guide you posted and I've actually been doing coli since this morning and then now and 3 of my dragons are at level 7. ;u; I just don't know whether I should get those stones that are being mentioned but yea, I'll try and train them as fast as I can.
If they're Might stones, skip them and save yourself the money. The Eliminate, ambush, and berserkers are essential, though.