Think of it kind of like a dog show Divination
Some will threaten your ability to do what your deck does
Endurance Bobblehead Intelligence Bobblehead Nuka-Cola Vending Machine Mystic Forge Panharmonicon The Prydwen, Steel Flagship Land (37) Ash Barrens Buried Ruin Clifftop Retreat Command Tower Evolving Wilds Exotic Orchard Ferrous Lake Glacial Fortress HELIOS One Irrigated Farmland Island x5 Mountain x4 Myriad Landscape Mystic Monastery Path of Ancestry Plains x4 Prairie Stream Razortide Bridge Rustvale Bridge Silverbluff Bridge Skycloud Expanse Spire of Industry Sulfur Falls Temple of Enlightenment Temple of Epiphany Terramorphic Expanse Treasure Vault Commander, Theme, and Strategy Ok, now this is what Im talking about
However, Runic Armasaur does require your opponents to be running specific cards -- creatures and lands that have activated abilities that aren't mana abilities -- which contributes to its inconsistency
One that definitely bothered me as a child who enjoyed seeing the otters at the zoo or aquarium was 1950s Beaver Valley , which somehow won an Oscar even with its persistent anti-otter smear campaign
Mizzix's last ability can't reduce the amount of colored mana you pay for a spell