What is more interesting is that, in Music Delighting the Ocean of Protectors, it is clearly mentioned of a certain Nyigma monastery that Dorje Shugden impersonated their protector:
Pretending to be Dragshul Wangpo, you tormented the oracle
By swallowing a vajra in his throat,
And repeatedly split his temple abode, and so on,
Praise to the terrifier of even the great gods
In detail:
Dharmapala demonstrated various miraculous emanations to Lelung Shepay Dorje
who tried various Tantric rituals such as wrathful fire puja to overcome him.
Therefore, to the common point view, they appeared to be at odds and, before
Lelung Shepay Dorje died, Dharmapala showed him wrathful emanations. In
somewhat of a wrathful aspect toward Lelung Shepay Dorje's teachings'
protector, Dragshul Wangpo, as well, with miraculous emanations he split his
temple abode at Lhaden Darpo Ling so that it collapsed. No matter how many
times it was reconstructed he would split it and destroy it again. Moreover,
pretending to be Dragshul Wangpo he entered the deity's oracle at Darpo Ling
and, shaking the oracle's body, swallowed a five?spoked vajra. Once it had lodged
in his throat he left the oracle's body. The vajra would not come out, the oracle
was in pain and at the verge of death. All of the benefactors and supplicants of the
deity were terrified. It became so bad that they invoked Gyalchen to enter the
oracle and then made offerings and supplications. He said, 'If you build a qualified
statue of Je Tsongkhapa in Darling Monastery I will perform the enlightening
activities!' As soon as they promised to do that, the vajra easily came out of the
oracle's throat. Here the praise is for revealing this kind of direct observable
evidence that develops faith and conviction.
After many years the building of the Darling protector palace was in ruins
so that, at one point, those in charge of the property from Tse Namgyal Dratsang
restored it. Responsibility for the construction was accepted from Thubten Dawa
by Dodam Dezur Kenchung who, in connection with invoking the Dharmapala of
Darling, removed the basal objects from the protector palace. He found an
extremely old tendö,
thread construction, that had been there many years.
Behind it, underneath a pile of various newer and older dö, thread crosses, was a
brass five?spoked vajra that the Darling Dharmapala took out and said, 'This is
Dorje Shugden's vajra!'
An accounting of it was given to Dezur Kenchung stating
only that such a vajra had been found behind the thread construction. Dodam
Kenchung himself wrote of wondering what was this vajra that had been taken
out and given to him by the Darling Dharmpala, of which no one, including the
previous oracle, had known was there. This story from previous times again
provides evidence for conviction and belief
On a quick search, Dragshul Wangpo appears linked to Dudjom Rinpoche: http://vimalatreasures.org/offering-and-invocation-of-dragshul-wangpos-concerned-activities-called-the-roar-of-hung.aspx
Is there a connection? hmmmm.
Maybe Dudjom Rinpoche's actions was due to this incident? Hmmmm. If there is, I would not blame Dudjom Rinpoche at all but I would forgive him with understanding.
I doubt that is the reason Dudjom Rinpoche was fearful of Dorje Shugden and caused him to create protective chakras against Dorje Shugden. If powerful fire rituals were ineffective against Dorje Shugden, how can these simple chakras be effective. Didn't all Nyingmas tried in vain to kill Dorje Shugden with their renowned fire rituals and didn't they fail? Whatever his reasons were, these chakras were definitely ineffective. Check out what they tried to do to Dorje Shugden :-
This is extracted from Music Delighting An Ocean of Protectors as well, page 103-104 :-
Then, although four undisputed powerful Tantricas,
With samadhi, began wrathful rituals to strike you down,
Through power of having completed Guyasamaja's two stages,
You would not be silenced, and showed signs of heroism, praise to you!
As for this, as related above, as soon as Tulku Dragpa Gyaltsen died, various miraculous manifestations occurred, and no matter what activities or rituals were attempted, nothing could be found to help stop them. In the fire?bird year manifestations had become extremely heightened, and in the earth?bird year the Great Fifth Dalai Lama built a new king protector house at the White Spring of Dol in to which various sorts of representational substances were placed, but it did not help. Many of the lay people were sick in an epidemic and several of the monks of Namgyal Tratsang had died. Such manifestations were stronger than even before and Namgyal Tratsang requested the Dalai Lama to take action.
Accordingly, to the Tratsang came Gadong Ngarampa Dondrub Gyatso, a vajra master of Dorje Drolo; the Fifth Dalai Lama, himself a supreme vajra master of Yang Sang Karma Dragpo, Super Secret Wrathful Karma Guru; two large groups of monks provided by Nangjung Ngachang Lozang Kyentse; the vajra master of Dorje Drak Tulku Pema Trinle; the vajra master of Mindrol Ling Terdag Lingpa Gyurme Dorje; Choje Ugja Lungpa; the Tantrica of Katsal Zurpa Ngari Konchog Lhundrup; thus a glorious mountain of Tulkus did seven ritual practices, from Wrathful Guru Padmasambhava, to Yamanataka, Kilaya, Logtrixxxvii, and so forth. On the comfortable broad eastern side of the Potala they did fire puja. The morning they were performing the ritual activity, one monk in Chagpori named Bodhisattva, who had clairvoyance, had a vision during his meditation. Early in the morning, from the direction of the Potala he saw small wrathful Deities emanating forth like atoms of sunbeams, going towards Drepung. Around eight in the morning he saw the Great King of Dol, master and servants, about to go to the Potala in a line on horseback in an impossible array of finery and ornamentation. The Fifth Dalai Lama performed the ritual activity but as he was doing it Sangpu Setrab emanated a monastery on top of Bumpa Ri, Vase Mountain, where none had been before and rocked the Potala Palace back and forth, which caused the Great Fifth's concentration to waver just slightly; and also by the power of Dragpa Gyaltsen, himself, having singlepointedly practised glorious Guyasamaja while he was alive and attained high experiential realizations of its two stages, the fire puja was not successful.
Likewise, when the great vajra master Dordrag Rigtzin peformed wrathful fire puja, Gyalchen came to the fire puja ladle but, when he turned the ladle over to pour into the fire he went to the backside of the ladle, and when he turned it upright, he was sitting on top again, and so on, and he was unable to burn him. When Mingling Terchen performed wrathful fire puja and Gyalchen came to the fire puja ladle, when he was about to put him in the fire, Setrab emanated a celestial mansion in the sky until Terchen's mind was distracted and he lost him from the ladle. The ritual monks saw a pigeon fly away. When Gadong Ngarampa performed fire puja, one of the ritual monks squeezed a dry apricot pit that flew up and struck the master in the head so that his samadhi dissipated and he was unable to burn him. Other teams of practitioners could not do it either. With fire pujas ineffective, the Great Fifth Dalai Lama, with an aspect of being disturbed, went to Sangpu Monastery and delivered a reprimanding address to Setrab in a very terrifying manner. As he was reading it, the Dharmapala was so scared the whole temple rocked and shook, it is said.