14 cards where (the text includes “whenever” and the text includes “becomes” and the text includes “tapped”) and it’s legal in Future Standard and the color identity ≤ GRW

Annie Flash, the Veteran (Outlaws of Thunder Junction #190)
Armored Scrapgorger (Phyrexia: All Will Be One #158)
Attentive Sunscribe (The Lost Caverns of Ixalan #4)
Hangar Scrounger (March of the Machine #142)
Phyrexian Atlas (Phyrexia: All Will Be One #237)
Radha, Coalition Warlord (Dominaria United #211)
Restless Bivouac (Wilds of Eldraine #257)
Restless Prairie (The Lost Caverns of Ixalan #281)
Restless Ridgeline (The Lost Caverns of Ixalan #283)
Samite Herbalist (Dominaria United #31)
Sunstreak Phoenix (Innistrad: Midnight Hunt #162)
Volatile Wanderglyph (The Lost Caverns of Ixalan #172)
Wylie Duke, Atiin Hero (Outlaws of Thunder Junction #239)
Zar Ojanen, Scion of Efrava (Dominaria United #227)

This search is finished. Now the real work can begin.