That pitcher often assaults batters with curve balls.
You don't say "to aggression." When you do aggression on someone, you're probably doing something to hurt them in some way. This is an attack, making this word to attack. This refers to a planned attack, though. Think about what you're going to do. Plan it out. Then, 攻める!
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: When you (I'm talking about you) attack something, you don't use weapons or thinking or anything silly like that. No, you use your intense sexiness (せ). Bam! So sexy. Attack!