I kinda wonder at this too. The siphon Kai described it as him "consuming [magic] from others", as he doesn't generate magic himself. Whereas channeling can come from various sources, both magical and non-magical (other witches, a doppelganger, celestial events, nature, and etc.), to obtain power. It seemed that channeling was more 'tapping' into power, as opposed to siphoning which seemed more intrusive and 'forcibly taking' power. Its like the siphon ability is a more developed/destructive form of channeling and they're actually different versions of the same ability.
Dryad was really, visually, stunning. But monster wise, probably the Arachne or Cyclops.
The siren's powers seemed subjective to the plot and weren't clearly defined. But given how Cade and Seline did use some of their mental powers on witches, I would say theoretically yes. Perhaps witches were simply resistant.
I also observed that the sirens apparently had to form a psychic link with another person to totally enthrall them — they seemed to only be able to implant psychic suggestions in other's minds otherwise — and this was probably why they didn't just mind control Beatrice into freeing them.
I wonder at that myself. Like Cade ripped out his own heart and was fine, but I think that the show should have made decapitation a fatal kill for most any immortal creature. But magic does bend the natural laws in the TVD universe, so I guess that the explanation.
I got used to it as well, but sometime I am like 😑 when it happens.
I just really got annoyed and confused by the strength levels displayed by these characters. Sometimes a two-century old vampire Damon or Stefan stood a chance against original vampire Eljha, whereas one of the first sired vampires in the shows history did not showcase such an even matched brawl.
I actually say Sybil and, to a lesser extant, Seline. Both had difficult childhoods and Sybil was forced into servitude than abandoned by her sister, who refused to apologize for making them both cannibals. Then in the end neither made amends and were suddenly killed by the Devil.
So long as the show can provided some 'sensible' reasons for the expulsion and reappearance of these creatures, then I say the new series has a chance. Also, give us a supernatural creature that can literally tear apart a VAMPIRE!!!!!!!
I gotta go with the Sirens! But in all seriousness, based on what we've seen about the Sirens, they'd need timing and an advantageous opportunity to have ample chance to kill an Original vampire; if we could have confirmed they can kill via their psychic powers then perhaps they stood a better chance. Now Cade, I say he could have killed them with hellflame no problem.