Neutral.
Character. Cost: 7. STR: 5.

Ally.

Reaction: After Jaqen H'ghar enters play, place a Valar Morghulis token on up to 3 different unique characters. If Jaqen H'ghar leaves play, discard those tokens from play.

Reaction: After you win a challenge in which Jaqen H'ghar is attacking alone, choose and kill a character with a Valar Morghulis token.

Joel Hustak
There Is My Claim #77.

Link: Decklists

Jaqen H'ghar
Reviews

If I win a challenge with Jaqen and a second character but then remove the second character from play before triggering Jaqen, for example via Tyrion Lannister (LoCR) by returning a Clansman to hand to raise claim, can I then trigger Jaqen for winning the claim alone? I'd have thought not, as he didn't WIN the claim alone but I'd like to clarify.

Yes, that works. The "attacking alone" situation was clarified in the official FAQ. https://thronesdb.com/faq#FAQ_7 — Odrl 1151