MySQL Select multiple column depending on column value

I searched the Internet and whole Stackoverlow twice, but didn't find a working solution.

Say I have a Table with following Columns: a,b,c,d,e,f,g,h,i

a is an integer which goes from 1-16 Depending on this value i have to choose if i select b-i.

Example: if a = 1 I need b,c,d,e,i. if a = 2 I need e,g,h,i

So I could use:

SELECT
CASE a WHEN 1 THEN b WHEN 2 THEN NULL ELSE NULL END as a
....
CASE a WHEN 1 THEN NULL WHEN 2 THEN g ELSE NULL END as g

Isn't there an easier way like:

CASE a When 1 (select b,c,d,e,i)?

Bonus wish: Can I select as depending on value of a? Example

if a = 1 column b should be named "lol", if a = 2 b should be called "rofl".