Kumano faces kakkazan bugs
Several issues with that card (and probably similar bugs with other cards of the same type = saga that transform into creature creature).
1: once they transform they don’t count as devotion. This means their CMC cost become 0.
This leads to have them targetable by cards like “March of the otherworldly light” as if they cost 0 (so for x=0).
However, here comes the second bug/interaction which is paradoxal.
2. Bomb ratchet still destroy them as if they have a mana cost of 1 (sac bomb ratchet with one counter). Meaning depending the interaction they are considered to have both 0 or 1 of CMC.
Either they keep a CMC of one and count as devotion or they have a CMC of 0 and don’t get targeted by things like blast zone and bomb ratchet that target things with 1 of CMC.
This is a paradox and needs to be fixed asap.
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[Deleted User] commented
Etchings of Kumano has a CMC of its front face but not the mana pips to add to devotion.
711.4b While a double-faced permanent’s back face is up, it has only the characteristics of its back face. However, its converted mana cost is calculated using the mana cost of its front face. If a permanent is copying the back face of a double-faced card (even if the card representing that copy is itself a double-faced card), the converted mana cost of that permanent is 0.