Just keep working up until you get to 240 light. Complete all the story missions and do your quests and you'll get there. The Heroic Strikes can be challenging. Some are easier than others, of course, and some of the strikes have been remixed. Regular Undying Mind is still haaaaaaaaard, while the remixed version with Taken enemies, is way easier. Valus Ta'aurc still sucks no matter what. Damn bullet sponge.
Run vanguard strikes. You get good loot. I can't wait to see what Xur brings.
Is the strike where you fight the boss in the dark an homage to a Dark Souls 2 boss? I think yes.