Not really on FFXIV tho but with StormBlood coming, lots of collab are going to happen with all the Final Fantasy mobile games
http://www.finalfantasy.jp/collabo/201706_ff14/

Including Final Fantasy Record Keeper where Haurchefant, alongside Estinien and Ysayle will be added as playable character! Haurchefant's fans (Ysayle's and Estinien's too), maybe you should have a look when it will be happening
It will launch on August 18th until August 28th and the event is titled "Souden no Ishigarudo"