You will surely see it in Simic Ramp decks both in Standard and Pioneer, alongside Hydroid Krasis and Uro, Titan of Nature's Wrath
They are generally some sort of activated effect or big X-cost spell that you can dump a ton of mana into for powerful results
(1) If this card is Synchro Summoned: You can add to your hand, or Special Summon (but its effects are negated), 1 Level 8 or higher monster from your Deck or GY that cannot be Normal Summoned/Set
And Gadwick, the Wizened draws a full grip of cards when it enters, then taps down key opposing creatures so your forces can get through
Making sure to include some lands that you can tap for any color will give you more chances and more options
Shanid and Dihada go hand-in-hand (especially because they were in the same precon, with The Reaver Cleaver