Should the Balor cast Blasphemy?

I say get rid of the Balor Guardian and bring back Frank and the rest of the Desperate Housewives crew. But I know I'm a minority of one on this issue.

Although none of the guardians were in the original module (each required a hard target search of each node to find a gem that did not match the node it was in, which then teleported the characters to its node), I prefer having them as cool boss encounters. Ideally, it shouldn't be a Balor, though.

Is it possible to have the party obtain information for how to defeat it? Perhaps Darley would know what the best spell buff combination is and advise the party to ready Counterspell dispel magic. If a good party kills her, then perhaps she has a journal.