Has Rotimi Amaechi, minister of transportation, lost his trenchant voice to the serpentine politics of Aso Rock? Has the fabled Lion of Ubima been emasculated and magicked into a wimpy cat? Has Chibuike Nwaamaechi, who defied a sitting president; survived lethal political machinations in his former party — the PDP — and fought against titans and celestials to deracinate an incumbent president, taken an oath of silence? Amaechi, known to be vivacious, vociferous and blunt, has suddenly retreated into a concrete shell. He rarely grants interviews and appears to be public shy – uncharacteristic o…