The spelling for säga is irregular. In colloquial writing it’s sometimes spelt säja.
I didn't realize that säga is cognate to say[English], sagen[German] and saga[Icelandic]. Interesting. :)
Swedish "ä" is pronounced as English /æ/. However, depending on a word, it might sometimes sound more like /e/.
The letter 'ä' is pronounced either /ɛ:/ or /ɛ/ (depending on whether it’s long or short), and before the letter 'r' it’s pronounced /æ:/ or /æ/. The letter 'e' is pronounced either /e:/ or /ɛ/ depending on whether it’s long or short. Also, as an exception, the word "är" is pronounced /e:/.