vine, creeper, to wind
藟 centers on climbing or trailing plants: a vine or creeper, and by extension the winding, twining motion they make.
藟 combines the grass radical 艹 with 畾, which likely acts as a phonetic component. The character is associated with winding plants, but the exact historical development is uncertain.
The grass top 艹 sits above a dense cluster of fields 畾. Imagine a vine creeping over and winding through a patchwork of fields, tying them together.
For ルイ, picture a vine winding around a ruined stone wall: ruined -> ルイ, and the vine's winding path matches the kanji's meaning.