1) Wait for the 'Diablo walks the Earth' message.
2) Go to Eldritch, thus making DC take Eldritch's spot.
3) Go to Shenk, kill Shenk's little buddies.
4) Go back to where DC is, get DC to chase you to Shenk.
5) Kill Shenk. Everything around Shenk dies, including DC.
6) Collect your charm.

with this one person can get the charm easily!!!
just get a anti idle in a game for like 3 hours and see if the msg appears and then u got ur charm