This is an idea on how to do it. It's not perfect as the NULLS will be sorted first. I'm sure that you'll be able to handle that.

DECLARE @RowCount int;

SELECT TABLE_CATALOG

,TABLE_SCHEMA

,TABLE_NAME

,COLUMN_NAME

,ORDINAL_POSITION

INTO #Columns

FROM INFORMATION_SCHEMA.columns;

SET @RowCount = @@ROWCOUNT;

WITH cteShort(N) AS(

SELECT TOP(15 - (@RowCount % 15)) N

FROM(VALUES(NULL),(NULL),(NULL),(NULL),(NULL), --5

(NULL),(NULL),(NULL),(NULL),(NULL), --10

(NULL),(NULL),(NULL),(NULL),(NULL))e(N) --15

)

SELECT *

FROM #Columns

UNION ALL

SELECT NULL

,NULL

,NULL

,'~~~'

,NULL

FROM cteShort

ORDER BY TABLE_CATALOG DESC;

DROP TABLE #Columns;