A concept ambigram, I suppose. The letters in 'MERCY' spell out 'WRATH' when rotated individually on their own respective pivotal axis. M->W; E->R; R->a; c->t and y->h. A more effective way to present this would be by placing the letters on individual gears, and see them rotate upon turning of a handle. Similar to Tom Banwell's brilliant ambigramautomaton.