Turning your commander into an artifact provides an interesting sort of protection
Or they allow them to attack without tapping
In other words, the guild keyword, which is going to be the strongest marker for the guild's mechanical feel, has to be on and about creatures
Then again, if you emphasize these mechanics this may be a plus to spice things up
So, why not try a Historic deck that used a bunch of your Standard cards AND is a huge chunk of cards that can be used in the corresponding Modern deck
23 Spells Birds of Paradise Llanowar Elf Elves Deep Shadow Deathrite Shaman Duress Thoughtsieze Scavenging Ooze Sakura Tribe Elder Sylvan Library Wall of Blossoms Hero's Downfall Maelstrom Pulse Pernicious Deed Bow of Nylea Courser of Kruphix Eternal Witness Den Protector Liliana of the Veil Reaper of the Wilds Vraska the Unseen Nissa, Worldwaker Tasigur, the Golden Fang Garruk, Apex Predator 17 Lands Treetop Village Llanowar Wastes Temple of Malady Overgrown Tomb Verdant Catacombs Twilight Mire Woodland Cemetery Urborg, Tomb of Yawgmoth Swamp Misty Rainforset Underground Sea Bayou Jungle Hollow 4x Forest I really really wanted Reaper of the Wilds to be a Siege Rhino, fairly unsurprisingly I guess