Oona's Prowler can other player mill me by activating ability many times?

[Soddda]

if I own and control Oona's Prowler and other activates the ability, who discards me or him? can he mill me like that?

[Arix]

Whoever activated the ability pays the cost.

Also, discarding is not milling.

[Soddda]

so what is milling because i heard ppl say that word

[Arix]

Milling is when cards are put from your library into your graveyard (or, less commonly, exile).

[Soddda]

so it is discarding, but from library?

[Arix]

No, discarding is always done from the hand.

[Clubby]

Milling is when cards are put from your library into your graveyard (or, less commonly, exile).

why do they call it "milling"?

[Arix]

It was named after Millstone.

[battlefield]

are you sure it's not named after Millikin?

[Arix]

Considering Millstone came first, no, it isn't.