Kurokami The Animation, Seikon no Qwaser Recommendations
Both are shounen series focused on contracts (usually between a guy and a girl) in which the one who fights absorbs the energy from his/her partner (the Tera in Kurokami, the Soma in SNQ).
Same genres: action, super powers, magic, supernatural.
SNQ has graphic ecchi content, while Kurokami doesn't.
Both have great animation, nice characters, and quite violent fights.