Battlescarred Alchemist

{1}{u}: Choose target creature you control. If
Battlescarred Alchemist is attacking, you may
instead choose target blocking creature. That
creature gets -1/+2 until end of turn.
{1}{r}: Choose target creature you control. If
Battlescarred Alchemist is attacking, you may
instead choose target blocking creature. That
creature gets +2/-1 until end of turn.
The "field" in "field testing" is the battlefield.