Here is a prime example of this motif in Luther's thinking. Citations indented below are drawn from Luther's own words, in different translations.
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. . . whoever teaches differently from what I have taught herein, or condemns me for it, he condemns God, and must be a child of Hell.
(Henry O'Connor, Luther's Own Statements, New York: Benziger Bros., 3rd ed., 1884, p. 20 / from Against Henry VIII, King of England, 1522)
. . . whoever teaches differently from what I have laid down here, or condemns me for any part of my doctrine, condemns God and is branded as a child of hell.
(Johannes Janssen, History of the German People From the Close of the Middle Ages, 16 vols., translated by A. M. Christie, St. Louis: B. Herder, 1910; originally 1891, vol. 3, p. 265)
. . . whoever teaches otherwise than I have taught, or condemns me, condemns God and must remain a child of hell.
(Hartmann Grisar, Luther, six volumes, translated by E. M. Lamond, edited by Luigi Cappadelta, London: Kegan Paul, Trench, Trubner and Co., 1913, vol. 5, p. 393)
. . . whoever teaches differently and anathematizes me (damns me) because of them, anathematizes God and must remain a child of hell; because I know that this teaching is not my teaching. This is to spite all devils and men who might turn this around.
(translation by Brigitte, a German-Canadian Lutheran)
. . . Whoever teaches differently on these points than I have taught, or who condemns me in these things, he condemns God, and must remain a child of hell; for I know that these doctrines are not my doctrines. Defiance to all devils and men who attempt to subvert them!
(The Life of Martin Luther: Related from Original Authorities, Moritz Meurer, H. Ludwig: 1848, p. 266)
The original polemical piece was written by Luther in Latin and entitled Contra Henricum Regem Angliae. Luther later composed a German version which differed in some respects from his original Latin; entitled Antwort auf Konig Hetirich's Yon Engelland Buck, wider seineu Tractat von der Babylonischen Gefangmss. It is from this version that the translations above are derived. Readers may consult the German primary source on page 229-230 of the standard Weimar collection (WA) 10(2) and also in the Erlangen edition, 28:346-347. It is a reply to the butcher-tyrant Henry VIII's book Assertio Septum Sacramentorum ("Defence of the Seven Sacraments").
This (paraphrased) "super-pope" / "I know everything" / "whoever disagrees with me is obviously damned" / "I don't claim to be a prophet but you better fear that I am" motif is found often in Luther. It doesn't flow merely from coarse and boorish style or loss of temper. He actually believes these things. I've documented many of the utterances in the following papers:
2) Martin Luther the "Super-Pope" and de facto Infallibility: With Extensive Documentation From Luther's Own Words
3) Martin Luther's Humility, Expressed in His Statements About Himself and His Mission (Hartmann Grisar)
4) Martin Luther the "Super-Pope" and de facto Infallibility: Extensive Documentation From Luther's Own Words and a Discussion of Protestant Charges Concerning Alleged Widespread Dishonesty of Catholic Apologists in Dealing With Luther (vs. "BJ Bear")
5) Heretic Popes and Pope as "God on Earth" vs. Luther as God's Man of the Hour and Quasi-Prophet (vs. Tim Enloe)
Here are some highlights of Luther's colorful, sadly self-deluded, megalomaniacal language (numbers refer to the papers above, where further documentation can be found):
. . . I shall no longer do you the honor of allowing you - or even an angel from heaven - to judge my teaching or to examine it. . . . I shall not have it judged by any man, not even by any angel. For since I am certain of it, I shall be your judge and even the angels' judge through this teaching . . . so that whoever does not accept my teaching may not be saved - for it is God's and not mine. Therefore, my judgment is also not mine but God's. (1) [July 1522]
I am certain that I have my dogmas from heaven, . . . (2) 
I say not that I am a prophet, but I do say that the more they despise me and esteem themselves, the more reason they have to fear that I may be a prophet . . . If I am not a prophet, yet for my own self I am certain that the Word of God is with me and not with them, for I have the Scriptures on my side, and they have only their own doctrine. (2) 
But I will allow no one to assail my teaching with impunity, since I know that it is not mine, but God's. (2) 
All who shun us and attack us secretly have departed from the faith . . . Just like Zwingli . . . It pains me that Zwingli and his followers take offence at my saying that 'what I write must be true.' (2)
We must needs decry the fanatics as damned . . . They actually dare to pick holes in our doctrine; . . . (2)
. . . I wrote so usefully and splendidly concerning the secular authorities as no teacher has ever done since Apostolic times, save perhaps St. Augustine; of this I may boast with a good conscience, relying on the testimony of the whole world. (3)
Not for a thousand years has God bestowed such great gifts on any bishop as He has onme . . . (3)
Chrysostom was a mere gossip. Jerome, the good Father, and lauder of nuns, understood precious little of Christianity. (3)
But who knows whether God has not raised me up and called me to this, and whether they have not cause to fear that they are condemning God in me? Do we not read in the Old Testament that God, as a rule, raised up only one prophet at a time? (3)