I like the theory that Mad Prophet is a hint. But I think the words 'five-legged' kind of point away from Ol'Emrakul. Are there any five-legged beings in the Multiverse? Or maybe it means that there are five of those shrews.
i currently don't know if i should add a third+ color and if yes which one ...
an idea would be to add ally creatures and use Cohort. But Blue/Red doesn't have much good ally creatures. White or Black would be my choice.
or Inspired Creatures, but for them i need tap effects too. (with Runed Stalactite i could combine both my Ally-Cohort and the Inspired idea)
something like Vampire Envoy might be nice because that Vamp does likes to be tapped ;P
Fathom Mage and Sage of Hours are also funny because they can utilize the +1/+1 counters which are placed on them.
Not a rules expert but since the creatures only untap when the spell resovles when your creatures get the chance to copy a spell the spell is not on the stack anymore so you can't copy it again.
He can copy the spell when it's on the stack before it resolves and then let the copy resolve to untap and then repeat.
In regards to Modern, consider this. Raging Ravine will probably be a 5/5 upon activation with this guy out. That it pumps land creatures should not be overlooked.
No seriously, it's great and has a lot of potential, but you can't really compare it to goyf. They fulfill very different purposes.
Not with Go For The Throat
UU
Counter target spell unless its controller pays 1.
If you have a clue, counter that spell instead.
Donate would be hilarious in this situation.
BTW: Donate and illusions of grandeur should definitely be in the same Limited environment!
Edit: Just found out that the pic was fake, so nevermind.
He can copy the spell when it's on the stack before it resolves and then let the copy resolve to untap and then repeat.