Fossils and Invoked engine, what can go wrong?
I've tried a lot of hybrid strategies with Fossils and I think this is the strongest one so far. The Invoked engine has decent synergy with the Fossil engine, as well as covering a good amount of Fossils' weaknesses.
Fossils are at their worst going 1st, whereas Invoked has gives you access to reasonable lines going 1st while not asking for too much deck space or many specific cards in hand. This is the biggest draw to this particular hybrid. I've also enjoyed using Fossils with other fusion archetypes because Weathering Soldier has good synergy with effects that send him to the GY, including fusion spells.
If given the choice we will go 2nd.
Main deck:
Nibiru - A big rock monster for Fossil Fusion, as well as a light to get access to Mechaba. He also has the benefit of setting up our opponent's GY for our Fossil Fusion and Invocation.
Kumongous - Kaiju's as a great way to both take care of annoying cards on our opponent's board as well as set up their GY for a Skullgios fusion. Kumongous gets the nod over Gameciel due to his Earth type. Extra deck space is limited in this deck and there is not room for the Water Invoked fusion. We're good at dumping attack onto the board, so the extra 200 attack from Kumongous won't be a problem.
Weathering Soldier - Our tutor for the Fossil archetype. Works when being fused with Invocation from the hand, as well as with Foolish Burial, Miracle Rupture, and Mathematician. He also beats down quite wel. Staple for all Fossil strats.
Aleister the Invoker - We're playing Invoked, so obviously we play him. Note he can choose any fusion monster, not just Invoked ones. This can lead to huge damage with Skullking, or even with a Skullgios if you played it off of Time Stream.
Mathematician - Aleister is obviously our #1 normal summon most of the time, but we won't always have him. Mathematician bulks up our count to help ensure we have a strong enabler to normal summon. Dumping Weathering Soldier or Keystone can be great, and he's also a 1500 attack monster to res off of Cross-Sheep.
Ash Blossom - Best hand trap in the game IMO. We are a going 2nd deck, so we want to be sure to load up on hand traps to disrupt our opponent from setting up an unbreakable board. She also gives access to Purgatrio.
Nemeses Keystone - An aptly named card, this is a key component in a lot of the plays our deck can make. Gives good value when fused off of Fossil Fusion or Invocation from the GY, helping to keep our hand stocked for Mechaba and Skull King. Not only that, but he's an easy access special summon to set up easy link summons (I'm looking at your, Cross-Sheep) and can recycle our fusions back into our extra deck.
Magical Meltdown - Tutors Aleister.
Dark Hole - I was running Lightning Storm, but the fact that we have Magical Meltdown in play a lot of the time made it a pretty big nonbo for the deck. We only get to play 1 Raigeki, so Dark Hole helps us get tasty fusion targets in our opponent's yard to set up our big plays.
Extra-Foolish Burial - The ultimate swiss army knife of the deck. It gets you missing combo pieces for fusion, or it can bin any of your fossils that work out of the GY. It has so many situations it's useful in that it's hard to list them all.
Fossil Fusion - Makes our Fossils.
Harpie's Feather Duster - This was another card that was Lightning Storm, but again that card was too much of a problem with Magical Meltdown. I wanted a main-deck out to Mystic Mine, and this is the best S/T removal in the game.
Invocation - Just 1 copy since Aleister can find it easily, and we have access to effectively 7 copies of him in the deck between him, Meltdown, and Terraforming.
Miracle Rupture - Sets up our GY as well as acts as a tutor when paired with Weathering Soldier. Don't leave home without 3.
Raigeki - The freshmaker. Easy, low-risk board removal. Raigeki is as Raigeki does.
Terraforming - Effectively copy #4 of Magical Meltdown, as we don't run any other field spells. Naturally if you wanted to side any field spells, this would act as a nice redundancy piece for them as well.
Time Stream - 3 may seem like a lot, but you really want to start with 1 in hand for the lines where you want it. If you can't easily make a big Fossil monster, you can make a Skull Bone, Time Stream it, remove if from GY to tutor another Time Stream, and then Time Stream the Skull Knight into either Skull King or Skullgios.
Impertinence - 2nd best hand trap in the game, and gives us some traps on the off chance we want them for Mechaba.
Extra deck:
Mechaba - Best Invoked monster. Easy access to it by normal summoning Aleister and linking him into Almiraj and then Secure Gardna.
Skullgios - Often the strongest Fossil Fusion. Not much to say here. Skullgios ends games.
Magellanica - We have a lot of Earth monsters, so this is an easy include. Nice and big to help us OTK. Conveniently also a Rock monster for Fossil Fusion.
Skull King - This is the fossil we most often will fuse in to, so we play 2. He's easier to access than Skullgios, and can often be better. He's also our strongest fossil monster to lead off with if we are forced to go first.
Augoeides - We make a lot of fusions, so this is a no brainer. Very often the best way to kill if our initial wave of fusions get answered.
Purgatrio - Ash Blossom and Almiraj give us access to this. Great on a lot of boards.
Skull Knight - Often just the in-between for Skull King or Skullgios. His remove from GY effect can also be relevant.
Skullgar - Less useful than his cousin Skull Bone, but sometimes exactly what you need. Notably the highest attack Cross-Sheep target in the deck.
Skull Bone - Sets up an easy Skull King or Skullgios with the aforementioned line using Time Stream.
Knightmare Phoenix - Having an MST in the extra deck is too useful. I never leave home without 1.
Secure Gardna - Almost strictly a Mechaba enabler, but he can sometimes clutch out a game by turning a simple Keystone -> Linkuriboh into 1000 attack.
Cross-Sheep - Always be on the look out for lines involving this little guy! He easily can turn what would be a turn shy 8000 damage into an OTK. Too many ways to enable him in the deck to list, so just be looking for it.
Linkuriboh - We have easy to play 1 star monsters, so we play Linkuriboh. Sometimes it's also nice to be able to force a Keystone into the GY to set up a fossil fusion.
Almiraj - Only needed for the Secure Gardna -> Mechaba line, which is extremely important.