Haha I'm actually typing an 11th grade research paper on this now and I have 2 but came to this site looking for a 3rd. The 2 I found are:
- repetition of the concept of death (lines 3, 6-7, and 11-12)
- Personification of the pen because it says "You still shall live---such virtue hath my pen--- / Where breath most breathes, ev'n in the mouths of men" (lines 13-14). The speaker gives the pen person-like qualities b/c of the Word 'virtue' (means "meritorious or good") ...he says it has virtue and therefore is personification.
sorry I can't help you with anymore but I'm searching for a good 3rd one and if I find one and have time, I'll post it here too.
Good luck!