Trying to consolidate data...I think

I originally posted the below under the formulas topic, but this may be more appropriate for a macro:

I have a worksheet with ~1300 rows of data and ~100 columns. Each row is unique and based on the data in the row, I'm using a formula to assign a "phase" to each row. Options are phase 1.1, 1.2, 2, or 3. One piece of data in each row is a master ID. Each master ID can be associated with 1 or more rows, i.e. 1 or more rows will have the same master ID. What I'm trying to do is if I have 5 rows with the same master ID, I want to be able to determine the latest phase among the 5 rows. So, if rows 1 - 4 are phase 1.1 and row 5 is phase 3, I want each of the 5 rows to indicate they're part of phase 3.

Column A is the phase for each row. Column C is where I want the last phase identified and column K contains the master ID.

Any help is appreciated!