Bug bite on ankle. Hurts, itches, swollen and bruised. About an inch from the bite is a cluster of liquid filled blisters. What could it be?

Bug bite reaction. Assuming it is definitely a bug bite, this is probably more bites or reaction to any venom injected by the insect. See your pcp if it doesn't improve quickly.
Allergy. Fluid-filled blisters usually signify an allergic reaction, likely from the bug bite. This should respond to a topical steroid cream. If the area becomes red, hot and painful, have it seen by a podiatrist. It could be infected.