Converting a string to dummy encoded variables
It is simple with python:

from pandas import DataFrame
data = [('2GRG822L9',"barbarians8,valkyrie5,chr_balloon3,fire_spirits8,minion8,firespirit_hut6,rage4,skeleton_horde3",1), ('8PYPY0LLQ',"valkyrie5,chr_witch4,hog_rider5,zapMachine1,mega_minion3,baby_dragon2,bomber7,skeleton_horde1",0)]
df = DataFrame.from_records(data,columns=('PlayerID', 'Characters', 'Result'))
df = df.drop('Characters', 1).join(df.Characters.str.get_dummies(','))


The result:

    PlayerID  Result  baby_dragon2  barbarians8  bomber7  chr_balloon3  \
0  2GRG822L9       1             0            1        0             1   
1  8PYPY0LLQ       0             1            0        1             0   

   chr_witch4  fire_spirits8  firespirit_hut6  hog_rider5  mega_minion3  \
0           0              1                1           0             0   
1           1              0                0           1             1   

   minion8  rage4  skeleton_horde1  skeleton_horde3  valkyrie5  zapMachine1  
0        1      1                0                1          1            0  
1        0      0                1                0          1            1