If not feel free to spam the mani katti bc after lyns mode it returns to full durability. Make sure you spend all your gold in lyns mode on good items and hang on to them so you can get a good gem on Lyn when she returns.
Some good units to use once you get past lyns mode is Lowen, Oswin, erk, Raven, Hector, and Marcus to name a few. Also make sure Matthew ( your theif ) gets some levels so he can steal everything he needs.
One more thing, during the early levels in Eliwoods mode there are reinforcements that arrive behind your units so they can kill merlinus, keep an eye out for that until about ch 20 .