Which legendary is the best?

Leviathan / Gryphon / Fenrir / Cerberus / Hydra / Satanic ???

U missed Hippopotus, Lava, Leshy, Angelo, Chrystal, Splashy, Roco and of cours Plantosaurus. (Behemoth|Plant, Chimaira|Electro, Sphinx|Fire, Phönix, Minotaur)

I think there is no best legendary monster, cause every legendary is a bit better then another...

circle theory

U missed Hippopotus, Lava, Leshy, Angelo, Chrystal, Splashy, Roco and of cours Plantosaurus. (Behemoth|Plant, Chimaira|Electro, Sphinx|Fire, Phönix, Minotaur)

I think there is no best legendary monster, cause every legendary is a bit better then another...

circle theory

Excellent answer!

There is no one monster that can beat all the others. There will always be a monster that can defeat it. There will always be a skill/talent combo that will be able to defeat each monster in this game.

However, personally, I would give the upper-hand to Cerberus at the moment. The reason why is because its speed is second only to Gryphion, has astoundingly high attack stat and it has Underdog. I find that it can more than handle its own against any monster, 1v1. Its defences aren't bad as well and it seems to be able to withstand even the best offensive skills of types with an advantage over it. Having said that, as I said above as well, there will be talent and skill combos that will certainly defeat it.
This is just my preference at the moment! (Minotaur seems to be popular among the other players as well, after they encounter it in Barren Land map 15 normal mode.)

Good luck!