In the central part of the west façade are two statues of Landsknechte (soldiers), representing the defence to the Turks in the 17th century and in niches at the third floor two statues of monarchs by Hans Brandstetter and Karl Lachner:
Ottokar II, Margrave of Styria (1084-1122) (Wikipedia).
Leopold V (1157-1194), the Virtuous, Duke of Austria (1177-1194) and Styria (1192-1194) (Wikipedia).
All other statues of emperors were removed in 1957.
Sculptor
Hans Brandstetter (Michlbach, Gemeinde Hitzendorf, Steiermark, 1854 - Graz 1925),
Austrian sculptor
(Wikipedia).