Scott Pilgrim vs. The World: The Game

Strikers are the "summons" that you can call on by pressing the Left Bumper during battle. These consume Gut Points (the same points that power your character's special attack), so if you are attempting to summon one and they don't come, that could be the cause.

There are four strikers in this game. Knives Chau, Mr. Chau, Mrs. Chau, and Nega-Knives. Each of the initial four characters starts with the ability to summon Knives, while the secret character summons Nega-Knives instead. Mr. and Mrs. Chau are unlocked as strikers by finding and defeating Mr. Chau on the map screen. Only the character that beats Mr. Chau will unlock the strikers, but the attacks are the same regardless of who calls them. If a character has unlocked Mr. and Mrs. Chau, you will not be able to control who is summoned. Mr. Chau will sometimes come out instead of Knives, and Mrs. Chau is rarer still.

Mr. Chau begins to appear randomly on the Map once you beat the Tood Ingram. You will recognize him as a character icon in black, standing on any of the available levels. If you enter a level he is not in, Mr. Chau will disappear and you will have to wait for him to reappear. If you go to the spot Mr. Chau is standing on, you will automatically begin the fight.

Unlike other levels in this game, if you lose a life while fighting Mr. Chau you will be sent back to the menu and Mr. Chau will disappear temporarily. But don't worry, he will continue to randomly appear occasionally after you clear an area. It is typically recommended to play "The Main Stage", as it is fairly short and also gives you an extra life for your trouble.

You will not be able to control which striker appears once you have unlocked Mr. and Mrs. Chau. Mr. Chau typically will show up at least once or twice every 10 times you use a striker. Mrs. Chau appeared for me every 15-20 times I summoned a striker.

There are some discussions that this could be a glitched achievement, and there's a series of steps that those who have unlocked it have taken to avoid possible glitches.

1) Make sure you unlocked Mr. and Mrs. Chau as strikers before you beat the game with any character.

2) Make sure that you have successfully summoned both Mr. and Mrs. Chau as strikers before you beat the game with any character.

3) Make sure you summon Knives with each playable character. Mr. and Mrs. Chau only need to be summoned by the character that first unlocked them.

4) Make sure the striker actually hits an enemy with the attack. You will be able to tell this has worked as the enemies will take damage or react to the technique. One that frequently causes confusion is Kim's. Knives causes damage as she's leaving after the kiss. So make sure that one hits as well.

5) Make sure you have unlocked the 5th playable character by beating story mode with all 4 original characters. His striker is unique and counts towards the achievement.

With these tips in mind, the hardest part becomes beating Mr. Chau. So good luck!

From Alita360:
"If you're coming here because the chievo glitched on you, here is a guide on how to "unglitch" it and get another chance at doing it: http://www.xbox360achievements.org/forum/showthread.php?t=25...

The first step in getting this achievement to pop is too beat the story mode with Scott, Ramona, Stills, and Kim. As soon as you start the first stage, hold the left and right trigger, then hit up up down down left right left right B A. This sacrifices a life and gives you 50 coins. repeat this step until you have 750 Canadian dollars. Pay off Scott's rental fees (It's the first shop after the sub-space highway), then max out your level and all you stats. from here, the game should take you roughly an hour.

Note: If you see a man in black standing on one of the stages on the level select screen, go there. The man is Mr. Chau, and is critical for the achievement.

After beating the game with all characters, you'll unlock Nega Scott.
Call Knives as Nega Scott.

If you've defeated Mr. Chau, load up whatever stage you want, and keep calling down strikers until both Mr. and Ms. Chau have made an appearance.

To confirm, there are four strikers in the game:

Knives Chau
Mr Chau
Mrs Chau
Nega-Knives

Nega-Knives can only be summoned by Nega-Scott, so this achievement represents having beaten the game with all the initially playable characters.

Extra hint for those who purchased the DLC! Knives cannot summon herself so when you play through as her there are only two possible strikers that appear: Mr and Mrs Chau. This increases the likelihood of seeing the mother appear.

****SPOILER****
Use default striker (Knives) with every character at least once, including Nega-Knives with Nega-Scott.

Unlock Mr./Ms. Chau and use them as well
^easy way to get Mr. Chau to appear on the map to fight is to beat the 2nd evil ex 3-5 times in a row. halfway point is fine

Make sure each striker's effect/attack actually effects (makes numbers appear)

Knives with:
Scott- makes "LOVE" with smoke and stuns everyone
Ramona- holds giant cup of coffee that heals 5 and makes you hyper
Stills- Jumps and throws giant kunai forward
Kim- Makes out with Kim and heals 15

Nega-Knives picks a target and deals 10 ish to them

Mr. Chau (aka Mr. "I wish I had this guy a lot sooner to help") teleports and slashes 2 guys for 20 each. replaces Knives once every 10 striker calls or so

Ms. Chau hits someone with a speech bubble..... useless, but as long as she doesn't just jump back up without doing anything you're good. replaces Knives once every 10 striker calls or so

To get this you need to call knives with Scott, Ramona, Stills, Kim and Nega Scott. Plus you need to call Mr. & Mrs. Chau as well. Sometime after you beat Todd Ingram(the Vegan) Mr. Chau will show up on one of the previously played areas, got to him and it starts a battle with him if you beat him it unlocks him and his wife as strikers. The you simply need to keep doing strikers until you get both Mr. & Mrs to appear. You only need to call them with one character not all of them, It unlocked for me after summoning Nega Knives with Nega scott after I'd unlocked him.

For those that are struggling to get Mr. Chau to even appear on the map this is what I did.

After repeating the final battle with Todd Ingram (Level 3.5) for what felt like 100 times across all characters. I had no luck and he just wouldn't appear for me so :(

I decided to clear my system cache and play offline as I read somewhere that it may help so why not? I went back and beat Todd a further 10 times but still no luck.

My last attempt was to quit back to the main menu and select a character at random, going on to the map and seeing if Chau was there and if not, I would quit back to the menu and try with another character. The characters I chose were in this order - Scott, Kim, Stills, Ramona, Scott, STILLS - when I went onto the map as Stills Mr. Chau appeared and I beat him easily with the power of love sword.

I went into the first level and pressed LB until him and his wife appeared and the achievement unlocked.

All I can say is that it seems as if it was all random luck, I had an awful time getting him to appear but clearing my system cache and using the quit to the menu method made him appear when there was no doubt that beating Todd over and over just wasn't working for me. If you're having the same trouble then give this a try and you might find that it works out, good luck!

I can also confirm that I did this when I had completed the game with all characters and had them all at level 16. I had used the Konami code and the power of love code many times as well as having completed the game once in CO-OP.

Hope this helped! :D