Rozen Maiden: Träumend, Fate/stay night Recommendations
Both anime involve mediums and their familiars. Both involve fighting, though the animation styles and undertones are much different. Both have tsunderes and strong female characters.
Although both anime are different in character design and style, they relate to each other the fact that there is a prize to be won in a battle royal. Magic and fantasy themes also play a role in both series.