This is a sentence from Digimon Adventure episode 3. I don't understand the 「おそってはきいしませんで」 part.
It's also important to state that the character speaks a Japanese dialect.
シードラモンは殺気を感じんかぎりおそってはきいしませんで
I interpret 「シードラモンは殺気を感じんかぎり」 as 「シードラモンは殺気を感じない限り」.
As long as Seadramon does not feel the thirst for blood...
I tried to think of 「きい」 as a vowel extension of 「気」 and rendered it as "When it attacks, we don't care" but that doesn't really make sense because when someone attacks, you care, right?