Seraph of New Capenna // Seraph of New Phyrexia

The compleation cycle of transforming Angels built each flip around a color-appropriate toll: pay in mana, or pay in the currency the color already trades on. Here the transform cost is a Phyrexian mana hybrid, so black's habitual willingness to spend life extends into the flip itself. Pay four generic and either black mana or two life, at sorcery speed, and a modest 2/2 evasive body reboots into a compleated attacker that eats your own board for temporary stats. That sacrifice trigger is what marks the back half as Phyrexian in mechanics as much as flavor: it wants tokens, spent artifacts, and creatures that have already done their job, and it converts that fodder into an attack-step damage spike rather than a standing threat. The design tension lives entirely in the two-turn commitment. Before the flip it is a cheap flier that asks for nothing and threatens little; the transform is a deliberate, sorcery-locked pivot that trades a whole turn of tempo for an engine that only pays off once you have built a board worth sacrificing. It is a graveyard-and-tokens payoff wearing a fair-creature disguise, and the Phyrexian mana keeps the flip live even when your lands are stuck, at the price of the resource black is always ready to burn.