Need a bit of advice

[Kornetto]

A friend has asked me to roll up a character for a game in which I can't play very frequently. The reasoning is that my character will be a higher level character, initially, who'll drift in and out (depending on when I can turn up) and a possible plot hook. So, in the spirit of being a wanderer, I decided to go with a ronin samurai. We workshopped the backstory to being an ex samurai of a feudal lord who decided to save the life of a baby in a town he was ordered to raise, instead of following orders. The inspiration for this was "lone wolf and cub". My question is: because carrying a baby into combat is too big an issue to be considered flavour, how can we represent this mechanically? I figured, maybe having some armoured backpack as a carrier and get flanking bonus when attacked from behind to represent the need to turn and protect his precious cargo. Any better suggestions?

[Urath DM]

I would look at that as the reason why he cannot always be present. When he can find a safe place to leave the child, your PC can appear; when he can't find such a place, he is not available.

The inspiration for the idea can only go so far. Acid-spitting creatures that dissolve the backpack and its contents are not something you'd expect to see in some settings... but in Pathfinder, yes. So consider that the differences in the setting may make *exact* duplication of the source inspiration impractical or even impossible.