In UBW route, if Lancer failed to save Rin from Kirei & Shinji, this is highly likely to occur.

Kirei needs only Rin's heart to summon Holy Grail, while her body is actually not necessary.
Meanwhile, Shinji is dreaming of Rin's body for a long time, especially her sexy legs, so he makes use of Rin's dead body and preservative magecraft to create his personally customized furniture:

Rin's legs on armchair (kept warm & fresh), Rin's body as private masturbator, and finally Rin's arm and head (filled with magic circuits) as wands & catalyst.