For the Black Captain:
Stay close to the left edge.
For his first attack (the small fireballs) you should be able to just tap a direction or hop and they will miss you.
Second attack (lightening + rolling balls) just jump.
Third attack (laser beam) jump on the mushroom until his beam runs out, then attack him when he is stunned.
Fourth attack (large fireballs) stand in-between where the two fireballs furthest from the Black Captain land. The furthest almost always lands right in the corner so use that for reference.
Final phase (balls fired at 3 heights) DO NOT SLIDE. Sliding takes to long and will almost always get you killed. Jump over low and medium height projectiles and walk under high ones. Hit the small gems at him to reduce his health. Keep moving after you do this as there will still be a few fireballs flying.
This tactic took me two or three tries, but would have taken one if I wasn't retarded. Good luck.
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