Yami (full name/title Tokoyami no Sumeragi [常闇ノ皇], meaning Emperor of Eternal Darkness) is the main villain in Ōkami and is also Amaterasu's archenemy. Despite having a name based in the first Vedic woman, this Yami is completly male.
He reappeared as the primary antagonist in Tatsunoko vs. Capcom: Cross Generation of Heroes and Ultimate All Stars, being the one responsible into merge the universes of Capcom and Tatsunoko together with the real world, causing a critical distortion that could've destroyed everything in this multiverse.
Yami is the final boss of the Arcade Mode. It originally appears in the Capcom game Okami. Yami is a giant character meaning that it is alone and it cannot flinch. Furthermore, being the final boss, Yami cannot be stunned and can perform a Hyper Combo any time it wants. Yami has three forms, each with powerful moves at its disposal.
If you defeat Yami, you'll get a special ending and a fourth alternate color for the character that lands the finishing blow.
As explained, Yami originated from Okami.
Yami stripped Amaterasu from her paint powers, but gave them back during the fight. In Tatsunoko vs Capcom, your heroes do not lose an ability and nothing is gained except a little health if you take enough damage. Yami's second and third forms in Tatsunoko vs. Capcom are actually its fourth and fifth states in Okami (the second and third are a green ball that can split into multiple pieces and a blue roulette wheel respectively). When the player defeats yellow-form Yami in Okami, Yami surprise attacks Amaterasu and enters its final giant hand form while Amaterasu has most of her strength wiped clean. In TvC, defeating yellow Yami will not damage the heroes, but there is an attack that Yami uses that is very similar to that which stripped Amaterasu of her power.
After the seventh battle in Arcade mode, the current battlefield will swirl. After a brief cutscene, Yami appears in front of the player's heroes. At first, Yami will appear as a dark ball with bright red lines. After defeating Yami once, Yami will become brighter and have similar, but yellow lines. Though this image does not show, Yami grows tentacle arms and legs in the second form. Finally, the third form grows a giant arm from Yami's body. The lines in the third form are as red as the first form.
NOTE: These are unofficial names. If you have a better or official name, please edit.
All of these can be blocked.
Hammer Strike - Most likely, Yami will begin the match with this move. Yami grows a giant hammer and pounds the ground with it. Nothing really happens until it jumps, then you must be careful. If you are using close combat, listen closely for a roar; when Yami does, use a launcher and super jump after Yami. Done correctly, Yami will not hurt you and you can still give Yami damage. If you are using projectiles to keep your distance, Yami's hammer will be useless if you are far away, but if it jumps then the earthquake can still hurt you. If you are either close up or far away, jump or crouch guard if Yami jumps.
Single Saw Slash - Yami will quickly spin while using a large, circular blade. There is also a Hyper Combo variation so be ready for that possibility. If you are using close combat, it is really easy to notice if Yami pulls out its blade. If you are using projectiles, the saw blade's range is still a problem. Yami always spins low for this move so either jump or crouch guard.
Missile Launch - A hatch on the top of Yami opens and canisters fly towards you. These are a tad slow and easy to spot but will deal fair damage. There is another version in which hatches from the side. If the missles are close, you can use a super jump or a very quick move like Zero's Hienkyaku.
Arm Sweep - Yami uses this move and almost nothing more. Yami will either use a high swing to catch you while you're airborne or a quick spin to attack you on the ground. Guarding is no problem, but pay attention to Yami's movements. If Yami's legs disappear you can confirm that it is using a lower attack; if it starts drawing back, then the attack is higher.
Cyclone Creation - Yami draws its hand back and releases a whirlwind that is as tall as the screen, but no more. A super jump can clear this no problem.
Lightning Projectiles - Yami brings its hand up to later throw a large ball of lightning. Super jumps can be used, but staying close to Yami will also keep you away from it. This is often confused with Hammer Fist so listen close for a roar; it will be the Electric Ball if it is silent.
Hammer Fist - Much like the Hammer Strike, however it is used for earthquakes only. Yami can still hurt you with its fist and can deal 2 hits if you are on the ground. Not only that, preparation looks exactly Electric Ball. Listen closely for a roar; it will be Hammer Fist if it roars. Do not get close and be in the air when it releases the attack.
Missle Launch - Just like First Form only Yami snaps its fingers and it always appears from above. When the missiles are close, use a quick movement to escape.
These moves either can NOT be blocked or will cause intense to massive damage.
Spiral Saw Slash - After glowing like the fighters, Yami grows 2 blades and spins multiple times. This must be blocked by crouching or jumping repetitively. It's not hard to decide how to dodge either Hyper Combo, just keep a large distance between you and Yami.
Energy Steal - This move does not do much damage and its range is small, but it is unblockable and can rob you of all of your current super level. Be ready to stay as far away as possible when you see Yami flash prior to the move.
Volt Crush - After flashing, Yami will grab you. After shocking you and dealing intense damage, Yami will throw you onto the ground. To avoid the grab, be prepared to super jump when it flashes.
Ninestrike Lazer - Yami will raise its arms like when preparing Volt Crush, but will pause a little longer. After that, it unleashes a ground projectile with a large height. If you super jump to brace for Volt Crush, you will still have time to jump again to avoid Volt Wave.
Great Incineration - Yami glows, then grabs you, after which it will unleash a long lasting beam that will take most of a full health bar, bringing you down to the brink even if you have enough health to survive. You can dodge by super jumping, but strangely enough you can evade by using the Mega Crash after being grabbed. Pay attention for when Yami holds its hand in front of itself. As comparison to Blaze Wave, there is a longer pause and so you can wait until the very last second to evade IF it is the Great Incineration.
Blaze Wave - Yami flashes, but raises its hand and uses its beam. The beam then swings, threatening ground enemies. It is not safe to super jump since being in the beam will deal more damage than when it swings. Prepare a crouching guard as this will bring the damage to a minimum.
Multiple Missile Launch - After Yami flashes once again, it will point at you and a lot of missiles will fall from above and explodes to the ground. This hyper combo is also unavoidable, but it can be blocked when you crouch on the ground or blocked in the air.