Sounds very good.

As for how Meyrin cuts herself open, she could do horizontal or vertical, or she could combine them into what's called a cross-cut.

Part of me wants to have her go horizontally like seppuku (Seppuku's my main fetish aside from asphyx), though vertically or cross-cut would allow her entrails to spill out easier, so she could, say, use a loop of small intestine as a makeshift dildo.