They activate super first, you activate super second, they kill you first, then your buddy kills them and they die second. Sounds good to me, or do you just want to tell every other class that they might as well not use a super while playing against a night stalker.
They activate super first, striker FoH. Striker wins.
They activate super first, Voidwalker Nova bombs. Voidwalker wins.
They activate super first, Gunslinger pops G-gun. Gunslinger wins.
They activate super first, Stormcaller uses storm trance. Landfall kills super. Stormcaller kills everyone twice.
They activate super. Defender throws suppression grenade. Defender wins.