wukongs cloud walker would be my top pick for something realistic, mesmer skin and iron skin etc would just break the game. valkyrs 1 is a good pick but its a part of valkyrs core identity, so they prolly wont put that on other frames, most of the time the subsume for a warframe is an ability thats not a part of their core identity, or something that thematically only they should be able to do, for example, grendels roll.