Hell only be able to keep one of them because of the legend rule, but this means that he can keep the version of Deadpool that now has menace and myriad and continue to steal the best text boxes every turn
Cecile, Haunted Mage),the only card with either Partner or Friends Forever that has access to three colours
Its best bet is probably in Pioneer, which doesn't have great wraths and has cards like Nykthos, Shrine to Nyx and Yorion, Sky Nomad that synergize with battles
Urzas Saga doesnt ask for too much work from you to make strong, especially given that cards like Sol Ring are Commander staples, but in decks with tons of cheap Artifacts, its an elite addition
You can use them to label zones or game pieces like a spindown that tracks your commander tax, experience counters, what have you
Id say good creatures, which we can cast of Mana Vault (because obviously, it has the best synergy with Nether Void)