Death warrants are supposed to be — Testament

Death warrants are supposed to be 1
An enginery of equity
A merciful mistake
A pencil in an Idol's Hand
A Devotee has oft consigned
To Crucifix or Block
(F.1409/J.1375)
[1] Death warrants:: testaments for distributing one's property after death.
[2] enginery of equity:: an arrangement of equal right.
[3] merciful mistake:: inheritance is a kind of merciful mistake, a result of law suit (hinted in line six).
[4] Idol:: one who draws his will with an idol's supreme power.
[5] Devotee:: one who devotes his trust on a testament. consigned:: transferred one's right.
[6] Crucifix:: a painful legacy law suit. Block:: a person resembling a block or log of wood (OED 15); an unintelligent, hard-hearted inheritor.