After activating Yomagna in two different matches, i had the following results
Match 1: I activated Yomagna, which was turned into a spellcaster by it’s own effect, and i intended to make Mixousia using an opponent’s non-spellcaster. The activation fizzled, upon resolution nothing happened in the client.
Match 2: I activated Yomagna, which was not affected by its type-changing effect, and i intended to make Mixousia using an opponent’s spellcaster. I was able to summon Mixousia, but i had to use Yomagna and one of my own spellcaster monsters.
The intended result in both these cases should be that the effect lets me fuse using the opponent’s monsters, as described in the card text. This should mirror Super Poly, except for the chain-ending effect.