Liliana Vess can i use 1st ability on target player no cards or must i target myself

[Tad]

if other player has no cards in his hand (since I used on him Liliana Vess 1st ability before in that game) and now I want to use her ability again so she gets another loyalty counter but other player has no cards left in his hand can I still use her ability on him or do I have to target myself? and what if neither of us has cards in hand?

[Aspirations]

Yes. You can use her ability on a player with no cards in hand.

The only targeting restriction is "target player" - discarding is just the action that takes place when it resolves. There's no requirement for the player to have any cards.

[Tad]

and just to confirm, liliana will still get the loyalty counter right?

[Aspirations]

Yup.