Invader of Darkness

Feel free to scroll down to the Deck Profile if you don't want to read the nitty-gritty, here. This is my attempt at casting the Invader of Darkness as a viable boss monster within a worthy deck, focusing on graveyard revival strategies, Squires and Dark Spirit cards for his consistent summoning and shutdown of quick-play spells (Chalice, MST, E. Teleport, B. of Moon, Super Poly, Cyclone, Controller, Twisters, etc). Depending on the match-up, Vanity's Fiend and Lair of Darkness can further shut down your opponent's ability to summon monsters and defend against the Invader!

I enjoy Allure and Upstart as draw cards that help prevent bricking, along with the first effect of Dark Spirit's Mastery as the primary search card for the Invader of Darkness (IOD). Usually, hard-drawing IOD isn't absolutely terrible: seeing him or Mastery in your opening hand, with Edea or Reinforcement, will bring out Invader of Darkness on your first turn. Play Mastery (If you don't have IOD in hand) to Discard 1 > Search & Add IOD > Normal summon Edea (or use Reinforcement to search Edea first) > Special summon Eidos > Use Eidos' effect to tribute both Squires to Tribute summon IOD. If you hard draw IOD and Mastery: Play Mastery > Discard IOD > add another IOD from your deck. (IOD is decent in the GY if you control a Dark Spirit monster). If you don't have / aren't able to get IOD to hand while controlling the Squires, Extra Deck plays can save you (thinking Phoenix / Unicorn). You can rebuild a board the turn after Tribute or Link summoning away the Squires: Banish Eidos from GY > Special summon Edea from GY > Special summon Eidos (from deck). The Squires' special summoning effects thrive when they're in the GY together.

I've tried Double Coston and Doomdog in the deck for reliable tribute summoning and searching for IOD, but think the Squires' ability to re-build a board (after being sent from Tribute / Link summoning or your own board wipe with Torrential Tribute), in addition to making tribute summoning easier in general is just too good for me to pass them up. The downsides are that their stats are terrible, Edea is a LIGHT type, and you need 3x of each to fuel the Squire engine but you do NOT want to hard-draw into Eidos; he is only useful in your deck, graveyard or on the field. (That's where Allure can help, along with cards like Mastery and Reincarnation that allow you to discard 1). If anyone has better ideas for low-level monsters, please share - I'm not currently incorporating Tuners / Synchros though I understand there's great DARK support in the Synchro world (Thinking Beelze).

GY revival strategies (however cheap they are), also work in summoning IOD quickly; Foolish Burial can send IOD while Reborn or Call of the Haunted can special summon him. By quick-effect, either Dark Spirit monster card can trade places with IOD in the GY. Foolish and a Malice in your opening hand, for example, means IOD will make an appearance on your field within a turn: Play Foolish > Send IOD to GY > Normal summon Malice > (set traps) > pass turn > Swap Malice for IOD (quick-effect) when your opponent does basically anything. (IOD loses his effect when summoned by a Dark Spirit, simply becoming a 2900 beatstick / eventual XYZ material, so this is not the primary strategy).

Vanity's Fiend is my current back-up boss monster for this deck, with his timing being crucial and summoning being conditional (a level 6, not searchable, can't be special summoned, etc). Ha Des and Neosphere are alternative back-up bosses in the side deck. Dark Necrofear could also work well (being a level 8 and searchable by Mastery, summonable with the Dark Spirits). In the extra deck, Zombiestien, Lancelot, Zombie Vamp and Queen of the Night can step in when the IOD isn't cutting it. Zombiestein is a beatstick with a single negate at the cost of detaching one and switching him to defense (DEF/1000). Lancelot can attack directly, pop one monster and negate one spell/trap. Queen of the Night requires 3x Level 8's so she hardly ever comes out, but two of her effects are useful: detach 1 to negate 1, or detach one to give a little attack boost to another monster. Thanatos (Rank-4) is great if Armageddon and Grepher are on the field and I want to make a heavy-hitter that becomes immune to card effect (quick-effect) by detaching 1. Break Sword is a great Rank-3 if you end up drawing several Dark Spirits, with his ability to destroy 2 cards (one of your own, one of your opponent's).

Lair of Darkness can really shut down some decks' engines if they are attribute-specific, so my side deck runs 3x copies. It doesn't do much against certain decks, sort of like Zombie World, which has a similar effect and is usually only sided-in for specific match-ups. Torrential Tribute can devastate your opponent and leave you relatively unharmed if you control the Squires. Once banished from you GY, Eidos will special summon Edea from the GY, who can special summon another Eidos from the Deck, allowing for a very easy Tribute summon of IOD (if he's in your hand), all while your opponent's board has been wiped. If you had Call in your back row when you activated Torrential, and you destroyed an IOD on your field, you can bring him back out through Call's revival.

If there are any suggestions, please let me know - thanks!