Abilities in riddle form?

[Tybit]

Some cards have their powers written in puzzle form? how do i know what it does in those cases

for example hill giant

[Arix]

That's not an ability. It's flavour text.

[Tybit]

then why would anyone choose to use it in their deck over the hundreds of cards that do have superpowers?

[DatAsh]

Because not all cards are made for constructed play, limited is a thing.

[Tybit]

what?

[DatAsh]

Sealed and draft, limited formats. Try using google if you want to know about those.