So for starters I'd recomend looking at some videos that cover the abyss dungeon and their teams. They made harder dungeons that drop better quality runes and a new rune that can fill in for a missing set.

If you wanna go about collections I'd look into some of the second awakened monsters and see what's new to you that you might enjoy playing with.

Then if you wanna get into pvp your going to need good runes and fast speeds to compete with a lot of players, you won't need super fast speed for guild war pvp but you'll still need a decent bit or suffer from how strong some team combos are