All living lifeforms are related one way or another.
Box jellyfish
Well, since jellyfish are all JELLYFISH that is a way they can be related, but otherwise, some are blue, and some are purple.
Closely related: obelia jellyfish Not closely related (but still related): coral sea anemone
The man o' war jellyfish has a powerful sting.
yes they are related
yes, you will become jellyfish man! or woman
great question, yes a portuguese man-of-war can kill a jellyfish.
First of all, the man-of-war is not a true jellyfish. Its body is filled with air. To be a jellyfish the "bag" of their body has to be filled with water. Also a box jellyfish is more dangerous. The box jellyfish is the most dangerous jellyfish in the world.
I'm not sure but I can tell you th letherback seaturtles eat jellyfish so maybe they eat man-of-war jellyfish. hope this was helpful.
No, or at least extremely distant. Dinosaurs are vertebrates, jellyfish are invertebrates.
The portuguese man of war is not a jellyfish because its sting cannot be cured by pouring vinegar.
A large box jellyfish or a man of war jellyfish could if it had very long tentacles.