I wouldn't even know where to begin, man. I just used basic colored sleeves for stuff. There's some cool colored dragon scale ones on Amazon that might work.

So, I did a little playtesting and actually found some success with Liliana's Specter at the 3 drop slot instead of Vampire Nighthawk. Of course the Nighthawk is amazing, and if you love it as much as I do, don't bother swapping it out. But the Specter does provide some extra control over your opponent while you're working toward your board wipe. It isn't as tough and doesn't bring as much combat utility as the Nighthawk either, but it still brings evasion, and works well with equipment. If you have a set, I'd suggest testing it out.

Plus, it makes the deck EVEN CHEAPER!

So, I did a little playtesting and actually found some success with Liliana's Specter at the 3 drop slot instead of Vampire Nighthawk. Of course the Nighthawk is amazing, and if you love it as much as I do, don't bother swapping it out. But the Specter does provide some extra control over your opponent while you're working toward your board wipe. It isn't as tough and doesn't bring as much combat utility as the Nighthawk either, but it still brings evasion, and works well with equipment. If you have a set, I'd suggest testing it out.

Plus, it makes the deck EVEN CHEAPER!

What do you think of Ogre Marauder in place of Vampire Nighthawk? Would it be worth sideboarding against some decks?

I think it could definitely work. It's not strictly better than the Nighthawk, but it serves the same functions.

What purpose does Vault Skirge Serve?

Provides evasion for Worldslayer and lifelink scales well with equipment. Not bad for a 1 drop.

I really enjoy how the lack of a downside to Inquisitor's Flail in this situation kind of acts as a Lashwrithe but cheaper and potentially more powerful.

Also, with this deck's increasing popularity, might you suggest something to add or substitute to make it a little more competitive? (Assuming we are willing to increase our budget)

If you want to make it more competitive, it needs to be in Dimir or maybe even Esper colors with a really consistent (expensive) Mana base. Aqueous Form would be a must.

Hey. I really like the deck and I'm going out to buy it today. My friend and I want to start going into some local modern tournaments, and I was wondering if you could do me a favor and post a more competitive version of this deck? I'd do it myself, but I'm still fairly new to Magic. Thank you!

Please refer to the comment directly above yours.

Like I said, I'm kinda new, and pretty dumb with building decks... but I'll take a shot at it.

You're welcome to start your own deck list and ask the community to assist with suggestions to build a more competitive version without budget constraints. Just give this deck credit in your description so nobody gives you crap about stealing the idea. Tag me in the comments and I'll come help too.

If you do decide to do that, I'd suggest Creeping Tar Pit as well as it provides another unblockable creature to push Worldslayer through with.

I tried doing some modifications to the deck, to grant it a bit more of a competitive edge; do you think you might be able to take a look and give your opinions on it: No Secrets, Just Death?

Worldslayer Survival & Combos

• Deathrender can work before and with Worldslayer (putting a new creature in play after Worldslayer activates).
• High-endurance mana sources, consider Dakmor Salvage, and the previously mentioned Darksteel Ingot. On this topic, you should of course still be running Darksteel Citadel. The best creatures this deck serves cost 2~3 black mana, meaning Citadel alone isn't super useful for replacing your lost creatures.
• Cauldron Haze is an Undying Evil alternative. Costs 1 more to cast but can save any number of creatures (gives -1/-1, so won't work with Vault Skirge).

Unblockable Fun

• Hot Soup is a strange Prowler's Helm alternative. Costs 1 less to cast, but 1 more to equip.
• Shimian Specter works well with the unblockable theme.

Lich's Toolbox

• Pariah's Shield makes you immortal
• Dead-Iron Sledge is slightly better than deathtouch and has no disadvantage

Land Stuff

With the goal of thinning the deck (draw cards you want sooner) but at the cost of slowing down the deck (up to 1 turn), consider Evolving Wilds and Terramorphic Expanse. (or spring for their more expensive fetchland cousins if you want them to come into play untapped)

Example: With 22 land target, including 4x Citadel and 4x Dakmor, 14 basic lands would remain. Drop half of those basic lands to put in 7 Wilds/Expanse.

Super good suggestions, thank you!

Any recommended cards for a sideboard?

This is really awesome. I've been slowly trying to get into modern more and this is a great inexpensive reference.

Shouldn't you add some removal other than Worldslayer, like maybe an Ultimate Price

Swiftfoot Boots for side maybe? or 2 of them in maindeck? To deal out with annoying blue decks that send criatures to graveyard or back to your hand...

I love this deck! Cheap and fun! Have you ever actually played it at a modern tournament?

Just some FNMs, nothing hardcore. It certainly holds its own. It's not going to consistently score you a top spot, but it's so much fun to play, you usually won't care.

I may well build it, then! I want to get into modern,at the FNM level, preferably without selling the soul of my firstborn child.

It's a good deck to get started with because it's cheap and fun in its regular form, and it gives you a decent platform to build a stronger deck off. Good luck!