blend vs combining

blend and combining both are nouns.

Word	Noun	Adjective	Verb	Adverb
blend	Yes	No	Yes	No
combining	Yes	No	No	No

As nouns, combining is a hypernym of blend; that is, combining is a word with a broader meaning than blend:

Other hypernyms of blend include combination, compounding.

blend (noun)	combining (noun)
the act of blending components together thoroughly	the act of combining things to form a new whole
a new word formed by joining two others and combining their meanings	an occurrence that results in things being united
an occurrence of thorough mixing

blend (verb)	combining (verb)
mix together different elements
combine into one
blend or harmonize