Lost Souls, U/W Spirits

Sure? This is more or less intended to play with friends or the folks at my local game store. The deck being cheap is just icing, lol

Just checking the parameters, as it changes my feedback based on the format and budget.

Off the bat, you want to cut it down to 60 if you can for consistency reasons. This also feeds into the other advice, so I'll let it ride below.

The main advice I can give is to cut down the curve to speed the deck up as much as you can. Right now, you've got literally nothing you can do turn 1, which means you're behind in almost every game, especially on the draw. That's sort of the opposite of what decks like this want. You ideally want to field a critter turn 1 and start the damage clock every game, then be playing a critter every turn after that and quickly overwhelm opponent with numbers, lord effects, and tempo. If you can drop a critter turns 1 and 2 then drop a lord turn 3, you've basically got the game in the bag assuming there's no nuke headed your way. That's the ideal setup, but even without the lord ready and waiting in hand, you'd rather have speed than power in a build like this.

For example, you'd rather play a 1-drop turn 1 than have to wait till turn 3 to drop an Uninvited Geist. Geist is stronger, 'harder' to block, and can buff itself, but dies just as easily to spot removal as a 1-drop and eats a much more important turn if it does, while the 1-drop gets some damage and tempo and goes 1 for 1 without costing you anything. Imagine it's your turn 3, you play your third land and tap out for the Geist, then opponent taps a land and Bolts it, then gets to untap into whatever he's planning to do. This speed-centric idea is extremely pleasant in spirit builds, as all your 1-drop options for critters come with great advantages, and combo with other parts of the deck perfectly.

And more good news, there are some killer spirits that are cheap, so you can get this done pretty easily and stick to a very reasonable budget. Check out Mausoleum Wanderer, Rattlechains, and Usher of the Fallen, all of which should be considered for this deck, and each of which costs less than a quarter.

For similar reasons, I'm going to argue against Door of Destinies (as well as the fact that it's a next to worthless topdeck and slows everything to a crawl if you get it in the opening hand) in favor of Rally the Ranks, as it's much faster, much more reliable, and basically can't miss. It also double buffs Katilda, which is nice.

Not Forgotten is an ok idea, as it either lets you recycle something good, get rid of something bad, or force opponent to topdeck something useless, all with the spirit kicker, but it's probably not worth 4 spots, as it's maximum effect would be as a topdeck rather than in the opening hand or early in the game when there's nothing you need it to do and you'd much rather have a critter to play. So I'd consider cutting it down to 2 spots.

Curiosity is in a bit of a weird spot in the build, as its material math is sort of all over the place. For example, you play it on a critter and attack, opponent Bolts the critter, and you're down 2 for 1 with even tempo. If you manage to land an attack with the critter (which this build is designed to do with all the flying), the card becomes a +0 (justifying itself), but nets you no benefit, as you could have achieved a better result with a Preordain, for example. You actually need to land 2 hits with the critter for it to really be of any value, as Curiosity itself doesn't do anything else. This idea is somewhat mitigated by Curious Obsession, which buffs the critter a bit, suddenly adding a better damage clock on top and being a little more justifiable as a card draw engine, but again, it's got the same material problems. You'd really only want to run it in a deck full of small/fast critters with flying that are essentially guaranteed to get around blocks quickly, which is what I'm advocating for tweak-wise, so you can take that or leave it.

Essence Flux is a good anti-removal card to hold up that you can also use for blocking tricks, but you've already got protection with Drogskol Captain and instant protection if you add Rattlechains (which you absolutely should), so you could consider cutting it entirely. It works on spot removal, but won't protect the critter from a nuke, which will be coming games 2 and 3 if any are available, and you'd do better with a mass protection card sideboarded anyway.

As for the sideboard, you can build a pretty solid one relatively cheaply. Check out Deafening Silence against control and storm, Damping Matrix against artifacts, combo, and creature based combo, Pithing Needle against specific threats like planeswalkers, lands, critters, etc (can usually be used to shut down a win condition), Rest in Peace against everything grave, and Make a Stand as an anti-nuke you can play games 2 and 3 that doubles as a little extra damage as well as a turn free of damage if you need it.

So, overall, I'd say cut 4 Hanged Executioner, 2 Uninvited Geist, 2 Not Forgotten, 2 Door of Destinies, 4 Dreamshackle Geist, 1 Temple of Enlightenment, and 4 Curiosity (leaving 15 spots) and add in 4 Mausoleum Wanderer, 4 Usher of the Fallen, 4 Rally the Ranks, and 3 Rattlechains.

For the sideboard, go with 2 Deafening Silence, 2 Damping Matrix, 2 Pithing Needle, 2 Rest in Peace, 3 Make a Stand, and 4 Sheltered by Ghosts.

You should be able to get all that for 10 bucks at any online retailer, so hopefully that fits in with the budget.

Just some thoughts, not trying to throw hate at the deck.