Tunnel

A piece of tribal hate aimed at a subtype that mattered for exactly one era of the game. When this was printed, Wall was load-bearing technology: the defender-shaped blockers of the period (Wall of Wood, Wall of Stone, Wall of Ice, Wall of Fire) were the premier ground-stall tools, and red, the color least able to grind through that stall, got the cheap pry bar for a single mana. The rate was never the issue. What dates the card is its target restriction, a window onto a design philosophy that treated narrow hate at a steep discount as a fair knob to turn, on the assumption the metagame would always hold enough Walls to make the trade pay. As the subtype stopped being load-bearing and defender migrated onto creatures of every shape and color, a spell that touches only things with the Wall type found less and less to point at. The no-regeneration rider belongs to the same moment, spending a line to shut a door a modern Wall would never think to open: sensible only in a world where regenerators were live concerns rather than rules trivia. Restriction and rider trace back to the same bet, that hating out a single creature type for one mana was a reasonable exchange for the narrowness. It survives as a snapshot of that wager, not as a card that still has work to do.