So, you're partial to 'phthsis', Uncle Dave? Good.

Here's a similar word which tickles my fancy:

chthonic
Pronunciation: \ˈthä-nik\
Function: adjective
Etymology: Greek chthon-, chthôn earth — more at humble
: of or relating to the underworld : infernal

Joe, your "Thou triumphedst" is incredible, though I have to agree I doubt if anybody has ever said it.

Today I chanced upon the combo 'triumph shall', and I thought that was a mouthful, but it takes a poor second place to "Thou triumphedst".