Logic Masters Deutschland e.V.

This puzzle is part of the Silent Killer series.

I. Hypertension
II. Kill the Messenger
III. Deadly Threat
IV. Regicide
V. Schrödinger's Cat
VI. Curiosity
VII. Down for the Count
VIII. Silent But Deadly

Normal Sudoku rules apply.

VAMPIRES - Each row, column, and box contains exactly one vampire cell, and vampire cells all contain different digits. Each vampire "drains" an orthogonally adjacent cell (its victim), increasing its natural value by the victim's digit and reducing the victim's value to zero. Two vampires can't drain the same victim, and the cell with the cross can never be a victim.

SILENT KILLER - Digits in a cage cannot repeat and their values sum to the value in the cell pointed at by the cage's northwest corner. Example: r6c1 is the sum of the cage in box 7.

SILENT LITTLE KILLER - The value of a cell with an arrow must equal the sum of the values on the arrow's diagonal.