Holy crap... I'm very open about not always understanding 100% of MTG's mechanics and all the different abilities and effects. Thrumming Stone and Relentless Rats though... every time I think I understand it, someone comes along and says "Nope, it gets better!"
I'll save the entire play-by-play except the last three turns. It's the last game of the night, and as per usual I'm doing badly. Mana screwed and playing against an Ezuri, Renegade Leader
elf deck that was insane ramped by turn 4 (4 Elf Warrior tokens with +7/+7 and Trample to give an idea) and a Sedris, the Traitor King zombie deck. Sed's got plenty of token blockers in play. Ezuri takes a swing with the 8/8s, Sed throws everything he has in defense, ends up only taking 5 damage. Ezuri regens one of the 8/8s, still plenty of other elfs on deck.
Sed's up next, he throws a Damnation. All I've got is a single Relentless Rats and a Grave Pact, and Liliana of the Dark Realms that just came out last turn so I'm good with it. I've got Thrumming Stone and 2 more Rats in-hand, 5 lands on the board. Draw Dark Ritual. Oh boy! Cast my Stone. No answers. Up Lil' by 1 to search for a land card & put it into my hand, put it on the board for my 6th swamp, play Dark Rit, and then cast my Rat, and start the cycle.
Now here's the fun part. I had understood Ripple 4 to be "Reveal 4 cards, if one is the same name as the last card cast, reveal 4 more" so that the cycle starts over with each Rat. I did not think it to mean that I get another Ripple 4 for every rat! If I draw into 2 or more rats in a row... it draws them all pretty much. So yeah... I've now got Thirty-Five 36/36 rats on turn 6. Turn 7, bring Marrow-Gnawer out for that extra insurance and take both out in one go.
Yeah, I did NOT think Thrumming Stone was so damned powerful with Relentless Rats... BOY was I mistaken! I could ramp this deck up even more, make it nothing but rats, tutors, stone and ramp... but that's no fun. It's not my style, and it's not my LGS's style. But.. just 'cause I didn't doesn't mean you folks can't! Have fun... but play nice! :)