relly hard riddle using strange words

please help with this

Paragon of a mute usurper, I.
To Occident and Orient adjunct.
Mine avocation, dearth to pacify,
By rubicund umbrage nigh-on defunct.

O, keen watchman to mine own, falter not,
To vouchsafe designs most astronomic.
Misplaced pursuit doth leave much truth forgot,
Affinity only one may mimic.

In anterior regard, quite absent,
Yet present, attending interregnum.
Contrary to self, mine heir apparent,
Abide, thou dost, foremost, and in tandem.

Confused, the vulgar see vengeful death's course,
Heaven's flute scourged, even focus slaughtered.
Yet displace determiner from this source,
A riotous assembly remembered.

Twixt conscience caught and more relative grounds,
All tears and woe be in our presence past.
At helm of craft, portentous death knell sounds.
Recurrent pause, wilt thou begun at last?

Is't a 'What'? Tis that thou thinkest of me?
Is't a 'Who'? Thrice shalt thou deceived be...