Just aim him when he appears haha.

Atlas, and burst him down.

yea atlas, usually roam has to get them, it's better if junglers/laners/carries can get another def item instead of atlas.

BF usually does combo attack where they wait till max heartthrob stacks before using skillA. im mostly on taka, so i usually try to disappear before BF completes his stacks.
if your hero has stun or something, use them on BF before he can complete his combo.