these moves are for near perfect coverage and being able to hit all mons in pbe for atleast neutral damage. aswell as also dealing both kingambit and tyranitar when it may be possible they use pursuit. timid allows mega gengar to outspeed adamant/modest non scarf dragapult. these moves can pair really well with support form ininciroar to help with gengar's lowerer physical defence stat and threarening other ghost and dark types notmally for atleast neutral damage when genger may need to protect expecting sucker punch. using both mega gengar's stabs is really useful with its 170 special atk stat. finally protect it nearly essencial for scouting out sucker punches although it can still function without it. the most preferable nature would be timid to be able to outspeed many mons without them using a choise scarf of boosting speed any otherway allowing you to deal massive damage and opponent will still be unable to switch. protect also works well peired next to anouther more offensive mon trapping threats allowing your teamate to deal damage and maybe even ko the threat