I once had an epiphany about
Marina. Why is she so good? It occured to me that what she really does is make the opposing character smaller. 7/5 is standard base stats for a 4* but often she's going to have both higher power and higher damage than the opposing character. So she has tremendous value.
I think a flex character is someone that almost always has a way of giving me an advantage when I draw them.
Marina can DR if you can't win, and she can win if her DR is opposed by SOA. My other favorite flex character was
Yayoi. SOA + DR is a topend defensive character, but 7/6 SOA is also an amazing bomb especially for Pusscats that don't need that much damage to win. She is also unpredictable. Her damage can't be stopped, so she is a huge KO threat.
Yookie was another character like this.
3* and 4* attack manipulation + SOA is also another popular flexible combo.
Rubie is a good example of this, as is
Gertjan.
I also like a high power pill manipulator like
Corvus. A pill manipulator can be used a bomb (pill forcer) that is immune to DR but can also be used as a wall.
Corvus is my 2nd favorite bomb in
Skeelz because of this flexibility. The only downside is they are not good as a 4th round anchor.
Protection power and damage characters are great teammates. They usually have good base stats and can also go against SOA.
Flexible characters, often both useful and unpredictable, demonstrate that you don't need raw 8 power to be a good character in
ELO.