stormtide

Your commander has to be legendary (or planeswalkers that say they can be your commander)

I'm not sure if that's legal, honestly, but you could use spawnsire of ulamog for that too

Add some homunculuses. They're great in these decks. Especially Doorkeeper

He could tag it casual so that's not a problem

I'd add gloomwidow's feast. Also Jungle Hollow is better than the guildgate. And lastly I'd add a little bit more black to make it worth it. Maybe doom blade or something. Other than that, great.

Good deck, but it doesn't follow commander rules. You can only have one of each non basic land card, and no card can have a colour symbol anywhere on it that's not a colour symbol on your commander. BTW, this is called colour identity

What will you replace him with

Just so you know, Palladium myr/2 gold myrs and 2 myr galvanizer makes infinite mana if you want to use it. Also I'd add shrine of loyal legions

You can't have forgotten ancient in here. It's not the colour of your commander

Too bad Athreos doesn't fit the colour scheme. He's even low mana, like you need...

These are the only cards I could find. Darn: why aren't there more bad cards in magic.
Witch Hunt
Lich
Also, it's not exactly obscure but near death experience might work to base a deck around
If You think these cards don't fit, that's fine. I just went looking and that's all I could find.

Death's presence

You can take out the black by replacing Madrush Cyclops with Cyclops of eternal fury, and find a replacement for violent ultimatum. Fog maybe?

A few cards good for lots of edhs:
Angelic field Marshal,
Bastion protector,
Command Beacon (which I think would make the commander cost normal),
commander's sphere,
Opal Palace,
Thunderfoot Baloth,
Tyrant's familiar

Add some more spells. Maybe fog and negate

Add the vintage tag to go with it. And maybe replace mono blue with multiplayer since they can see that in the picture

I know it's instant/sorcery but no creatures? I'd add a few walls like fog bank, and wall of frost. Also, I'm not sure if you can tag it creatureless with talrand. Also, I'd add a few cards that give you no maximum hand size for a bigger range of available spells: Reliquary Tower, Spellbook, Thought Vessel, Venser's Journal, and maybe Graceful Adept

There's only 50 cards

I'd find a few more creatures. You have so many instants you won't be able to hold off any attacks without killing off your creatures

You might want to either tag or rename the deck. The current name makes it easy to confuse it with the decks that use no lands