The Hell/Extreme difficulty in Survival mode requires you to defeat 100 enemies in a row without dying to get the "Back From Hell" trophy. The enemies start out easy and keep getting harder as you progress. The easiest way to complete it is to select Ken or Ryu and spam their Shoryuken special move (Right, Down, Right, Triangle). You must be able to perform this move perfectly so you never fail with it and can press the buttons very quickly. Practice it until you perform this move 100% perfectly every time. When the match starts, always spam this attack until you land the first hit. While the enemy is down, double press to the right to push them into the corner. Once they are in the corner, there is nothing they can do. Just keep spamming Shoryuken to easily defeat all 100 enemies with no skill required. You can still get perfect victories after round 90+ by spamming only this one move. The reason the Shoryuken move is so effective is because it is a really quick attack that covers the area in front of you and above you. So when the enemy is cornered, it does not leave them much choice. They cannot jump over you because your attack covers the air. They cannot land a heavy attack because your Shoryuken is much faster and will hit them first. The best they can attempt is a throw or quick (weak) punch. Your Shoryuken is just too fast for them and covers too much area. It does not leave the AI much choice other than blocking and doing quick punches. Do not even bother with blocking enemy attacks -- just keep spamming Shoryuken and it will act as a counterattack. Shoryuken also deals more damage in one hit than most enemy attacks do. So even if they hit you, your attack deals them more damage. The AI simply reacts to whatever buttons you press and "calculates" that your Shoryuken will do them more harm than they can cause you. So all they do is stand around and try to block. The following are some additional tips:

During the first 10 rounds, concentrate on getting lots of points and select the Double Down supplements for a score bonus.

During the first 30 rounds, do not refill health after every match to save points -- so you have enough points later when you need them.

After round 50, always refill your health after every match.

After round 50, if your health is still full after a match, select the Defense supplement and ignore all other supplements.

You also need a little bit of luck because of how random the supplements are. If you get a low health boost five times in a row, it will get tricky. If that happens, just retry and hope for better luck next time.