Six Six is a powerful mill and recursion tool for graveyard decks, but you dont even need to care about the graveyard to run this since its a self-fueling engine
A quick search of Scryfall reveals over 850 instances of the text "at the beginning of your upkeep," so there's a plethora of options when producing a Commander deck based around upkeep triggers
The morph is rarely of use, particularly as the only monster in the A cube with morph somewhat reducing the surprise factor
As such, if you have Castle Locthwain in your collection, you should play it, but if you don't, I'd make this the lowest-priority card in the deck to spend your wildcards on (although it is worth adding to your collection if you are interested in Explorer or Historic because a lot of decks play it)
These points can be used to exchange for cards, if you have your heart set on a particular one (Pidgey hive rise up)