I'd like to see if Zaros and Seren's "composition" determines the likelihood of them fusing. For example, if Seren has the dark shard, then she'd be more "compatible" with Zaros' dark nature, and if Zaros was given the light simulacrum, he'd be more compatible with Seren's light nature. Perhaps this could then inform whether or not would be the "dominant" personality of the fusion. If you chose the dark simulacrum and kept the dark shard, your choices emphasize "darkness", allowing Zaros to be dominant. Conversely, if you chose the light simulacrum and discarded the dark shard, your choices would be skew towards "light", making Seren dominant. If you chose the dark simulacrum and discarded the dark shard, then Zaros and Seren would skew towards their own respective elements, while the light simulacrum and using the dark shard would put them opposed to their natures.
I'm curious which of those last two possibilities would make them a "perfect" fusion that corresponds closest to replicating Mah. There are four possible combinations there, so while that might be a bit too much to develop, it would offer some overlap between our picks in how they are now.
25-Dec-2016 22:39:52