The Rune of Punishment sounds great in theory, but was absolutely worthless for most of the game, at least in IV (it did became badass in Tactics). SIV was so easy that it never mattered, but it's (lack of) usefulness is only rivaled by the V's Dawn Rune, where the first spell is... a group antidote.
I also agree with WK's last post almost completely... but how is II's major battle system your LEAST favorite? It is better than I's and at least involves some strategy. I might even rank it ahead of IV's because it reminds me of having to sail around the world map for half of the game.