Earthlore

The activation clause carries the entire design: this Aura only boosts a creature that is already blocking, and only when the enchanted land is untapped. Tapping that land becomes the cost, which turns a one-mana enchantment into a repeatable defensive trick you can fire each turn you choose to hold back. It is free in mana but priced in tempo, since the land cannot also be making mana that turn. The toughness-heavy bump (more padding than punch) marks the intent plainly: this keeps a chump blocker alive turn after turn rather than swinging a race. You respond after blocks are declared, the same timing window as the instant-speed pump that eventually made this whole category obsolete. The land-Aura idiom that converts a standing permanent into recurring combat value was a recognizable part of this set's vocabulary, a way of handling combat math through enchantments before flash-speed effects proved cleaner and more flexible at the same job. What lingers is the historical fingerprint: a defensive tool built for a grinder content to give up the offensive option entirely, paying a land's worth of mana production every turn for the privilege of surviving the block.