Combating Flash
As I’m sure I’ve made it abundantly clear, Flash is extremely susceptible to Precision Strike. Characters that can add Running Shot to the mix are key here (I’m looking at you, Captain Boomerang). As always Outwit can shut down a speedster’s mobility and it’s no different with Wally. When attacking Flash, be aware of his Probability control. If you can attack him from outside of 6 squares, he won’t be making you re-roll your attack. 

If you're playing Golden Age, Kid Zoom is a cheap way to neuter The Flash's Hypersonic Speed right away...

Continued Below...

Special Objects Recommendations:
• Legion Ring – This is a great way to increase the Flash’s mobility from the start.
• Suit of Sorrows – This will allow you to use objects from increased damage, ignore Shape change and protect Flash from being Mind Controlled.

Conclusion
At a cost of 150 points Flash will take up half your team in a standard game. Nevertheless, he’s a great choice for his points and with the right support; he can be very challenging to take down.