You're question is of a personal nature, we can't make up you're mind for you.
I honestly think you should get both...but if you had to choose one i would say the mythic. Plus legendary might become free soon...
Get the Mythic(800 Microsoft points) and the Heroic (Free)
when you bought ODST, it should have come with another disk; the Mythic mappack disk. plug in this disk and multeplayer will be yours! it comes with ALL maps, even legendary and mythic maps, and has forge and theatre and all that good stuff.
how the f*** should i know?!
After you complete Mothership Zeta and return to the Wasteland, you will find the blaster in the exact place where it was before. If you fast travel to The site and keep walk past all the crap left over and you should see a dead alien with a Blaster and ammo
You'll need to play story mode as an Alien. When in the level "The Mothership" you'll need to destroy these purple bunches of rock on the walls with your laser beam. After you destroy them complete the level. After the level there should be a level on the mothership that's called "Varan". Play the level and beat Varan and afterwards he should be available to buy at the store.
No
on any legendary(just that it should be a strong or rare legendary)
yes, yes it should
everyone should have at least one legendary like Ive 41
You can get the blind skull at Sierra 117 at the first fight. Hug the wall to the right all the way to the cliff and there should be a ledge with a skull on it. Yay! You found the blind skull!
you should get a dsactionreplay