There are tons of extremely powerful effects that become even better when doubled up, like Portal to Phyrexia's ability to force your opponents to sacrifice three creatures when it comes into play, now forcing all your opponents to sacrifice six creatures instead
Two of the best and most refreshing designs here are ostensibly Voltron in nature
You must follow all normal timing rules when casting a spell with web-slinging
Muldrotha, the Gravetide $7.98 Muldrotha, the Gravetide returns to Standard after its original run from Dominaria
Hold that three blue up to threaten an opponent during their turn, forcing them to cast something nonthreatening so they dont lose it to your counter, and then draw two cards at the end of their turn anyway
Bruenor is another source of free equips, something that makes more expensive Equipment a lot better