For those who need a closer place to learn this spell:
I learned this one off of Thread Leeches in Korroloka Tunnel.
I was getting discouraged when all I kept seeing was TP Drainkiss, but sooner rather than later they started using MP Drainkiss and I got it off of the 3rd one.
I got this @ 35 with capped BLU Magic(108 @ 35).
Good luck.