Key combo that started the idea:
Bloodhall Ooze
+
Hardened Scales
, plus a black synergetic permanent:
A) Bloodhall Ooze
+
Hardened Scales
+
Retribution of the Ancients
B) Bloodhall Ooze
+
Hardened Scales
+
Rakdos Cackler
Which results in four +1/+1 counters each turn on the Ooze. Plus a 3/3 or an enchantment that can eat your Ooze's schmooze to kill off potential blockers.
Or you use Bloodhall Ooze
+
Bramblewood Paragon
for trample.
Further big one-drop beaters besides
Bloodhall Ooze
that use counters and profit from Hardened Scales:
Hardened Scales
+
Rakdos Cackler
Experiment One
+
Hardened Scales
Hardened Scales
+
Skarrgan Pit-Skulk
And the two-drops:Hangarback Walker
+
Hardened Scales
Avatar of the Resolute
+
Hardened Scales
With all those one-drops, Avatar of the Resolute will also usually be huge by itself.
What's also huge with your counter-enhanced creatures and Hardened Scales are proliferate spells:Hardened Scales
+
Volt Charge
: Lightning Bolt and a pseudo double Glorious Anthem.Hardened Scales
+
Tezzeret's Gambit
: Divination and a pseudo double Glorious Anthem
-Volt Charge is an amazing combat trick in this deck-To some extent that's true for Inspiring Call too, which is more often than not a Shamanic Revelation for three mana at instant speed... that protects your dudes from boardwipes.
ALL the other synergies:(Well, basically I'm listing pretty much all cards profit from counters on the creatures, or put more counters on them.)
Hangarback Walker
+
Hardened Scales
Experiment One
+
Rakdos Cackler
Bloodhall Ooze
+
Experiment One
Avatar of the Resolute
+
Oran-Rief, the Vastwood
Bramblewood Paragon
+
Oran-Rief, the Vastwood
Hangarback Walker
+
Oran-Rief, the Vastwood
Hangarback Walker
+
Quest for the Gemblades
: That's a gamble when your opponent has ways to exile or bounce your stuff.
But if it works out, the value here is huge.Even better:Hangarback Walker
+
Oran-Rief, the Vastwood
+
Quest for the Gemblades
And to make this ridiculous outcome even more unlikely, add either Hardened Scales or AotR:Oran-Rief, the Vastwood + Hangarback Walker + Quest for the Gemblades + Avatar of the ResoluteOran-Rief, the Vastwood + Hangarback Walker + Quest for the Gemblades + Hardened Scales
