Luke 22:3

Εἰσῆλθε δὲ Σατανᾶς εἰς Ἰούδαν τὸν ἐπικαλούμενον Ἰσκαριώτην, ὄντα ἐκ τοῦ ἀριθμοῦ τῶν δώδεκα.

RBT Greek Interlinear:

Strongs 1525; Eisēlthen; Εἰσῆλθεν; Entered; V-AIA-3S

Strongs 1161; de; δὲ; and; Conj

Strongs 4567; Satanas; Σατανᾶς; Adversary; N-NMS

Strongs 1519; eis; εἰς; into; Prep

Strongs 2455; Ioudan; Ἰούδαν; Judas; N-AMS

Strongs 3588; ton; τὸν; the; Art-AMS

Strongs 2564; kaloumenon; καλούμενον; he who is being called; V-PPM/P-AMS

Strongs 2469; Iskariōtēn; Ἰσκαριώτην; Iscariot; N-AMS

Strongs 1510; onta; ὄντα; who is being; V-PPA-AMS

Strongs 1537; ek; ἐκ; from out; Prep

Strongs 3588; tou; τοῦ; the; Art-GMS

Strongs 706; arithmou; ἀριθμοῦ; number; N-GMS

Strongs 3588; tōn; τῶν; the; Art-GMP

Strongs 1427; dōdeka; δώδεκα; twelve; Adj-GMP

RBT Translation:

Not of the Twelve (a Thirteenth)

And an adversary entered into Praised One ("Judas") the one who is being summoned as Man of Cities ("Iscariot"), he who is being out of the Number of the Two and Ten.

ὄντα ἐκ - being out of

I.4 - to express separation or distinction from a number, ἐκ πολέων πίσυρες four out of many, Il. 15.680; or

I.5 - of Position, outside of, beyond, chiefly in early writers, ἐκ βελέων out of shot, Il. 14.130, etc.; ἐκ καπνοῦ out of the smoke, Od. 19.7; ἐκ πατρίδος banished from oneʼs country, ἐκ μέσου κατῆστο sat down apart from the company, Hdt. 3.83;

In other words, what one would expect here is ὄντα τοῦ ἀριθμοῦ — the added ἐκ (out of) is wholly unnecessary to read "being of the number".

(cf. LSJ ἐκ)

Julia Smith Literal 1876 Translation:
And Satan came into Judas called Iscariot, being of the number of the twelve.

LITV Translation:
And Satan entered into Judas, the one having been called Iscariot, being of the number of the Twelve.