Rearranged my potions id, making BloodMagic potion effect starting with 215+, getting crashes: http://hastebin.com/yugijeqape.pl

You can't have potion ids that are above 127 from, what I understand.

Hm...says who? I dumped the potion IDs with NEI and there's potions way over 256. Like 300, 500, 600, even 999 is there.

You could assign values over 127, but because of how vanilla works anything over 127 causes it to return a negative number, then it errors and crashes. Don't blame us, just how it works as vanilla never expected needing this many potion effect slots.