Stabilizing an unstable system and removing oscillations from step response
The OP has a mistake in the numerator vector as there is an additional space between the minus sign and the 1.027e14 coefficient which will cause that to operate as an expression (-2.58e13 - 1.027e14) instead of negate the sign.
Had the system been correct, the resulting closed loop system with the compensator and gain chosen is underdamped. This can be resolved in this case by lowering the gain such that the closed loop poles are equidistant from the real and imaginary axis. Further details below.
The  resulting ringing is because the closed loop poles are too close to the $j\omega$ axis relative the the distance to the real axis, an underdamped system. The root locus shown by the OP shows all the possible closed loop pole locations depending on what loop gain is used, and thus as is with the current controller chosen the OP can lower the gain to select a condition with closed loop poles equidistant from both axis (which is an ideal trade of settling time and ringing). The general considerations for closed loop pole locations are summarized in the chart below.