Rules glossary
↑ Parent rule: 506.4 A permanent is removed from combat if it leaves the battlefi…
506.4d A permanent that’s both a blocking creature and a planeswalker that’s being attacked is removed from combat if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that’s being attacked, whichever is appropriate.
No sub-rules.