Hi there,
As the title states. I was able to use Mementotlan Fusion to fuse away a Fiendsmith Sequence and fiendsmith engraver to make aerial eater and dodge an effect veiler on my sequence. Mementotlan fusion states i need to use a memento monster as material, however I was able to complete a fusion summon without this requirement.
Please see the link to video excerpt for the issue.
Cheers.