Common Lorcana cards are identified by a grey, circular globe-like symbol
As for getting those noncreature spells your opponents left on the top of their library, Decadent Dragon, Gonti, Lord of Luxury, and Thief of Sanity will do a fine job of taking them for your casting
Thankfully, over the past decade, even Wizards has realized that partners are pretty broken, and now they avoid printing more cards with the mechanic, instead relying on various partner-with-style mechanics that do something similar but with a much smaller pool of cards to choose from, like how you can partner a Doctor's companion with a Doctor from the Doctor Who set
Its role in Commander is obvious turning any noncombat damage you deal to an opponent into card advantage
Immediately, creature removal, blocking, and attacking became virtually hopeless affairs
What are your favorite forms of evasion