Many games of EDH end up being stalemates as boards accumulate resources, and if we're able to connect with any creature while Marisi is on the battlefield, we get to break that stalemate
This is a little counterintuitive since planeswalkers are supposed to represent specific characters that dont have different identities on different planes, but you can 100% own three copies of a Jace, Liliana, Teferi, etc
Sableye Sableye is the ideal starter, and with 2 great attacks
You pay all costs and follow all timing rules for lands played and spells cast this way
Of course, what color you play affects the quality of removal you have access to thanks to the existence of Magics color pie
Planeswalkers will enter the battlefield with double the normal number of loyalty counters