You can get Nightshade reagent from the forest tile directly above
the shrine of sacrifice (just north of Paws) simply stand on it and
search at the new moon. Note that this tile is MUCH closer to the
Mandrake reagent tile.
Go in the secret dungeon entrance at lord british's castle, and
use four down spells, then use and exit spell. You will
appear next to dungeon hythloth. re-enter dungeon, explore and
you will find a magic orb. Use the magic orb, cast exit spell,
re-enter and repeat as wanted. (you need over 600 HP to do
this!) This gives you +5 intelligence, strength, and dexterity,
but takes OFF 600 hp each time!
Also, head west from dungeon hythloth to find the balloon.