Xanathar can do a wide variety of strategies decently well just like a lot of other commanders, but its main ability allows you to lock opponents out, which is as powerful for you as it is annoying for them
You can choose to phase out a single creature for just one white mana, or you can phase out all creatures controlled by a player if you pay the kicker cost
Karumonix, the Rat King is a Legendary creature phyrexian rat card in Magic: the Gathering MTG
I've found this rabbit legend to be quite popular, but it gets scary real fast, and forces opponents to deal with it, which isn't too hard when you're drawing everyone a bunch of cards
It's not like the main set got finished and then Commander picked up the scraps: Jirina is a main character of the set and gets to sit on the front of this deck
If you do plan on investing heavily into one creature, consider adding blue in order to counter your opponent's removal