Convergence Lattice
COMPLEX HAZARD 20DC 40 Thievery (master) or DC 35 Religion (master) four times to obliterate each of the four key runes.
A DC 45 Thievery (legendary) check (or breaking the lattice) stops the clockwork's movement and prevents it from resetting, but doesn't stop its current activation.
(3 actions) The convergence lattice uses its first action to call for aid. Each convergent creature within 100 feet of the lattice Strides toward the lattice as a reaction. Creatures thus called continue to move toward the lattice on their turn each round until they are adjacent to it, at which point they defend it with their lives.
The lattice uses its second action to deal 16d6 mental damage (DC 42 basic Will save) to a non-convergent creature within 100 feet. This damage is nonlethal; a creature knocked out by this damage doesn't gain the dying condition and is automatically Controlled by the convergence lattice when they awaken.
The lattice uses its third action to make the same attack against a second non-convergent creature within 100 feet; if there isn't such a second creature, it doesn't take its third action.