Deoxys-D in my experience does not in fact carry taunt, only SR, Spikes, Magic Coat, and attack, so I use my gliscor to sub up and toxic it. Wait for it to die, then toxic stall the rest of a HO team. They all need turns of setup, so toxic and then sub + protect to beat them. They never hold lum berries, only power boosting items. I can also use tyranitar to OHKO it after it gets a layer of SR, but I prefer gliscor as it nets major momentum for me.