This combination can have a fair bit of mechanical synergy. The warlock’s spellcasting ability can be set on Charisma and lined up with the herald’s, allowing you to focus on Strength and Charisma. While the warlock’s spellcasting is points-based and the herald’s is slotbased, you’ll at least be able to cast your low-level spells virtually at will. All in all, not the most optimal combination, but enough synergy to not regret picking it. Flavor might be a different story, depending on the archetypes chosen for the component classes. The base class flavor of the herald and warlock clash almost as much as the artificer and druid classes do, though archetypes can eliminate this contrast entirely, which means that leaning into or out of the contrast is entirely up to the player. More levels of herald will give you a standard ideologically-driven magical warrior with perhaps a secret dark side or a bit of extra magical help from a friendly supernatural entity. More levels of warlock will create a more powerful spellcaster with a streak of toughmindedness and combat prowess. An equal mix gives you a unique but viable fighting spellcaster. [[Synergy Feats for Multiclassers#Herald w/ Warlock|Herald-Warlock chains and ideas]]