Pyros
<Silver Donator>
Actually Medusa might not be done, they did a complete design rework on her(changed her icon, her textures colors and shit like that, and incidentally her particles to match the new style). Well she might be done now but maybe not last week when they decided what to add to the patch. Could also be because of the remake, I read similar stuff. Hoping for 6.77 this weekend so we'll see, hope Icefrog doesn't overdo the reworks again though, his last batch of reworks were over the top for most of them(centaur ulti, jakiro ice path, drow aura).Shredder came in the Legion Commander patch I'm pretty sure, which was like December 2011 or something? It's been about a year.
Medusa's basically done, speculation about why she's not in yet includes talk of a remake in the next Dota patch, which should be out next week or so.
And you're right about Shredder, thought he was older but he was in fact added with the Skywrath/Legion Commander/Xin patch, which is a very recent batch of heroes, 6.73. I don't really know any of these "new" heroes anyway, also don't really care about most of the other not added heroes but the 2 I mentionned so not a big deal for me who gets first. I do know I don't give a fuck about Medusa though. I wouldn't mind Frost Wyrm over most of the older heroes either.