Here's something broken...

Unknown

Mage-Ring Responder and Gideon. Play the Responder, add Vigilance. 'Nuff said.

raidan

I tried this, I failed to see how it was broken.

It allowed the Mage-Ring responder to defend, but it's activated ability on attack did not activate.

This left me with a 7/7 wall for 15 mana. Not bad, however since it's hard to get a match 5 to make it attack, I feel it is lacking compared to other rare/uncommon white creatures.

Was there some other ability with this combo that you might be referring to?

Unknown

Anything that is match-5 (and match-4, kind of) instantly gets a sideways look from me. It relies too much on chance.

Unknown

Yeah, I was mostly referring to the fact that for 9? Loyalty and 1 or 2 decent mana cascades, you can have an 8/8 defender. Sure, he doesn't attack, but with the respite that gives, you can easily reinforce him and/or put out other units (looking at you, Hangarback Walker).

Unknown

For 4 more, you can get Iroas's Champion, which is a boardwipe in creature form.
For 3 less, you can get Relic Seeker, which is only one less in power and toughness until it becomes renowned and can grow every turn or grow another creature.