Getting a readable baseline
The way into a virtualized chunk is to control the input. Obfuscating something minimal like local foo = "bar" - which compiles to a single LOADK - yields a ~65 KiB file from a 20-byte source, but you know exactly what it must ultimately do. First you fight anti-beautify measures: invalid string escapes (\!, \:, \#) that Lua silently ignores but formatters choke on, and semicolon traps like (foo)[1] = "bar";(bar)[1] = "foo"; where stripping the semicolon makes Lua reinterpret "bar"(bar) as a call and crash. Then you locate the entry point - here a table returned and invoked by colon syntax (:Mj()(...)), which implicitly passes the table as Self.
Peeling the abstraction: inlining, junk, control flow
The entry point is almost entirely nested function calls into factorized helpers. You recover the logic by inlining: a helper called once that just returns U[30446] becomes that index inline, peeling one layer at a time. Layered on top is control-flow obfuscation - helpers driven by a state variable (if L > 47 then ... L = 66) that you unwind statically when simple or dynamically when not - and junk code you detect by deleting blocks and re-running to see if the script still works. Unpacking main reveals it mostly populates a helper table (h_funcs) - string.match, string.byte, bit ops, the constant decryptor - which you rename from opaque integer keys (h_funcs[12] -> h_funcs["safe_tbl_unpack"]) to readable identifiers. This renaming, by tracing what each function does, is the most time-consuming part.
The dispatch loop and lifting opcodes
Every VM is a fetch-execute loop. Here it is a repeat ... until false with a tree of if Enum < N branches, where Enum is the opcode id read from each instruction (e.g. 45 might be OP_ADD, 12 OP_MOV). Using the standard Lua opcode definitions (see Part 1), you lift renumbered Enums back to real opcodes: some map directly (Stk[REG_B[VIP]] = nil is OP_NIL), some are large (a full OP_CLOSURE with upvalue handling), and some are custom (an OP_XOR that has no native Lua equivalent). Hardened VMs add runtime anti-tamper: a hidden pcall(unpack, {}, 0, 2147483647) reliably segfaults Lua 5.1, and sensitive opcodes like OP_CONCAT crash the moment you try to print their operands - so they leak nothing under naive inspection. The same VM-in-VM shape guards browser fingerprinting scripts.