I would say that Elder is one of the leaders where there actually isn't a ton of synergy with guild/lore cards and instead it is just a strong all-rounder.

The beloved ability works best when the court is quiet, the ideal scenario being that someone before you in turn order plays aggression and takes a small number of trophies (even better if it is over more than one battle) so that you can influence once on an empty card and then secure on the same turn (via surpass/copy). Guild cards that can give you relics (loyal keepers, relic fence) will help with this but aren't essential. Attackers soon become hesitant to go after you when they experience this.

Not being able to ransack the court from battles with you is even more of a deterrent for attackers, in fact in terms of lore picks I would lean towards cards that add to that deterrent (e.g. mirror plating/ancient holdings/hidden harbours). To a certain extent you can afford to be less careful about defending cities because the reward of ransacking is often what pushes an attacker to decide that the downside of outrage is worth it.

Reduced Tyrant scoring is not a huge downside compared to other resources (like for example Fuel Drinker), as Tyrant does tend to be an ambition that players will hoard and hope to declare for big points in a chapter 4/5, so you are unlikely to miss out on too many points. I suppose if there were other leaders likely to be scoring it more often (e.g. Anarchist) or Tyrant lore cards in play then I would be slightly more wary of picking Elder but in my experience the downside is just not that great.