Let's talk about on how to trade units for Merit Points. If you have excess units that you do not want to use for fusion, you can use it to trade for Merit Points.
1. First, you need to go to the Administration Office and tap "Missions".
2. Tap "Trade" to access the Trading System.
3. Then tap "Trade Units" in order to enter the Trading Units System.
4. See the small circle on the upper right of each unit icon? Tap it if you want to trade it for Merit Points. Let's take Golem as an example it's value is 700 Merit Points. Note that Points will differ depending on the level and rarity of the unit.
Once you're done choosing the units, tap "Trade".
5. Tap "Yes" if you want to proceed.
6. A confirmation dialogue will appear for every successful trade.
7. Please note that there is a limit as to how much Merit Points you can acquire from trading units. You can only acquire 50,000 Merit Points per day.
Do you know that you can trade Zel and Karma too? You can check the article for more details.