Suspicious Detonation

The real number here isn't the printed five: it's the two you actually pay when the discount fires. Sacrifice an artifact this turn and Detonation drops to for four damage to a creature, a rate that would be aggressively costed on its own. The design bolts that reward to a very specific condition, and the condition tells you which deck it was built for: a shell already cracking Treasures, Clues, Food, or any other artifact token for incidental value, where the sacrifice is happening anyway rather than being paid grudgingly as a cost. The uncounterable clause, spelled out to include ward, is where the card does something a plain burn spell can't. Cheap creature removal is precisely what gets stranded against a protected threat or a control opponent holding up interaction; here the spell can't be countered, so the ward-taxed threat takes its four whether or not the defender kept a counterspell up. The condition that keeps the rate in check is the tempo asymmetry it imposes when you whiff: without the artifact sacrifice, you are laying out the full five for a sorcery-speed spell that can only point at creatures, and the card quietly reminds you it was never meant to be cast that way. It is a conditional reward dressed as a removal spell, and the condition is the whole point.