Fisguinho

Ok some hints in the order of riddle you posted

[spoiler]

- Think of explosions.... BIG ONES!!

-It's a card released in a recent expansion, he obviously likes metal and death(maybe)

-She is either …

[spoiler] I'm gonna need some more help for the number 13 and vampire hunter. For the number 13 as said before there are 3 cards for the phobia and none trigered it. For the vampire one i tried every werewolf/bear/rat, …

Thank you, managed to get everything with those hints, thought i had searched it already for the second riddle but apparently never entered the page for it

Managed to do most until: 

"According to a spooky rumor, the set was never finished as the creator died while he was making it."

Got no idea what it might be.

Also missing:

"The …

indeed, tho it was a first thoughts for me so i didnt have the whole picture

poisonous and a discover makes it seem amazing for arena, doesnt seem that good for constructed tho

we already saw these types of cards before, but the cost might actually save this one

we already saw videos on how powerful this card can be, forget the stats just look at the battlecry

this card seems great... then again this card seems horrible to face

the immune part + 1 mana means that with a cost reduction we can see yogg shenanigans with pyroblasts.... PREPARE FOR FIREWORKS

7 mana flame strike with frost nova eh

Rush hunter with a bunch of rush beasts?

I can see this be played on token druid or something along those lines

Personally i feel like a delayed silence can be better than the instant silence if all you want to do is delay the game

Finally some more secret counter carrds :D

seems nice in high cost combo decks but still on the pricey side

guess who's back, back again

doesnt seem good enough to make the cut

seems really good with all the imps running around

mechatun combo i gess