Loads of people don't know how crucial adjusting your item build is.
Luna is the kind of hero who wants all the huge items but going Satanic first is an awful idea, the first one you should always get is a BKB for sure.
Having a nuke as a carry, along with one of the strongest level 1 ults means you can focus less on damage items first and more on survivability, except all these idiots go agi treads, poormans and helm of the dominator instantly. Not only do shields suck massive richard on ranged heroes, you have like, 600 HP and explode in a few hits.
Magic immunity on squishy heroes is a must, and having free damage lets you pump that out and still be useful. It's like how the older traditional way to play Anti-Mage was a Vanguard into Manta, so you were more useful, since mana burn does great damage. Now people opt for a Battlefury since his blink allows ridiculous farming, as well as a good escape if you're caught out. The problem with doing that is that they sacrifice his early game contribution, but dumb pubs go Battlefury AM and still try and fight with just that, only to find out they still can't do much with no health.
Luna is also one of those heroes that is more likely to be a terrible pub player, like the stereotyped Riki and Sniper pickers. Coincidentally they also build stuffty items like VLADS FIRST EVERY HERO and Shadow Blade every game despite not even needing it and Manta rush on Sniper being so much stronger due to headshots proccing on illusions, as well as headshot being the best skill to max first since it boosts your DPS by a little under 50 every shot on average.
I should just stick to playing Invoker because he's so strong at all points you get to set the game flow early. He's also incredibly hard to outlane due to his versatility. Usually leads to me netting some kills in the sidelanes and hopefully going something like 5-0 heading into the midgame. I just hate when people ask me to run to their pushed out lane to gank when I already have a global presence for when they realize you can't gank pushed lanes.
