Guardian of the Great Door
The tax here runs backward from convoke: instead of tapping permanents to reduce a spell's cost, you tap four of them as flat overhead on top of the two white pips. What that overhead buys is a 4/4 flier for two mana, a body that would be absurdly underpriced without the fine print. The design math is a tempo trade dressed as a mana discount. The four-permanent tap accelerates nothing; it strips your board of blockers, attackers, and mana on the turn you deploy, so deploying it spends a developed position rather than building toward one. That makes it a payoff for going wide first and cashing in later, closer in spirit to the old batch-tapping mechanics than to any ramp effect. The tap targets are deliberately loose (artifacts, creatures, or lands, in any mix), which keeps the requirement from becoming a color or archetype straitjacket while still demanding four untapped things to spare. The tension the design resolves is how to print a genuinely oversized evasive body at two mana without making it castable on an empty board: the answer is that the cost is real, it just isn't paid in mana. Whether the 4/4 flier justifies the board you tap out to get it is the question posed at every casting.
