  The abundance of bulk and boundary topologies in higher-order topological
phases offer remarkable tunability and diversity to boundary states but also
pose a challenge to their unified topological characterization. In this work,
we propose a theoretical framework to characterize time-reversal invariant
topological superconductors hosting Majorana Kramers pairs (MKP) of corner
states by using a series of spin Bott indices, which capture both bulk and
boundary states topology. The developed invariants can characterize MKP in
arbitrarily shaped systems and all distinct spatial distribution patterns of
MKP. As an illustrative example, we apply our theory to analyze the Kane-Mele
model with sublattice-dependent superconducting pairing potentials. In this
representative model, various patterns of MKP can be engineered through edge
cleavage, and despite their high sensitivity to boundary terminations, MKP can
be faithfully characterized by the proposed topological invariants.
