To execute judgment (ποιησα κρισιν). "To do justice."

To convict (ελεγξα). First aorist (effective) active infinitive like ποιησα before it.

Ungodly (ασεβεις). See verse Jude 1:4 and end of this verse.

Of ungodliness (ασεβειας). Old word as in Romans 1:18, plural in Jude 1:18 as in Romans 11:26.

Which (ων). Genitive by attraction from α (cognate accusative with ησεβησαν, old verb, to act impiously, here alone in N.T. save some MSS. in 2. Peter 2:6) to agree with the antecedent εργων (deeds).

Hard things (σκληρων). Harsh, rough things as in John 6:60.

Which (ων). Genitive by attraction from α (object of ελαλησαν, first aorist active indicative of λαλεω) to the case of the antecedent σκληρων. Four times in this verse as a sort of refrain ασεβεις (twice), ασεβειασ, ησεβησαν.