Mr. Fred’s tactics
First I would not allow a flayer to have two bodies on the same plane. Or alternate prime material plane.
So from the attic of abyss Mr. Fred goes to sleep and roams the astral where he can invade Barry Bond Bard dream.
Now for Barry to wake himself up an opposed will check against Mr. Fred. Using detect thoughts, which the bard would get a saving throw, Fred would pick Barry’s brain.
“Tell Mr. Bond what did you do last summer”, questions Mr. Fred.
Barry, “Never,” However loses save.
“I know what you did last summer. Very interesting, I wonder if the king would like do know about you and his daughter”.
I would give saves to prevent Mr. Fred from totally picking the players mind.
Since my players defeated Mr. Fred from Speaker in the Dreams, I gave them full xp. I am planning of giving him half xp. And adding classes to bluff him up.
Coming from astral plane to prime. Blast the party four times a night especially to keep the spell casters from recovering their spells. I will allow a ten percent chance of the thread being broken. I would hit and run tactics for a week or two, then nothing. Leave alone for a week or two, during which time I would be advancing other plans. If I can successfully pick their minds, I would upset their plans. Gee Mr. Dragon do you know this party in Southfork is planning on raiding your lair. Just thought to be neighborly. Or pop in their home town, drain some brain. And call out that you did this for the glory of your master Mr. Barry Bond Bard.
Minions would depend on size and level of the party.
Grimlocks Kobolds, goblins, and hobgoblins with class levels.