frostdread cuirasa is a player item, it has nothing to do with pets
heart of the mountain is good because the pet is good
winterking is a bit of trap because it suggests a hybrid style, which isn’t great but doable, but mostly it just takes better slots/stuff with modifiers
as for build using mindweaver Builds using Bysmiel's Mindweaver item - Grim Dawn Builds
bysmiel trinkets was literally one of the strongest pet builds at a time, to the point it got pets nerfed, and has been staple/favourite in Maya’s pet collection in her “Birb” dominated pet build themes The Carnival - A Guide to Pets
Builds using Bysmiel's Mark item - Grim Dawn Builds
Builds using Bysmiel's Grasp item - Grim Dawn Builds
retal drain essence is good
blood knight is not a retal set, never was
builds using guardian’s of deaths’ gates Builds using Mythical Guardian of Death's Gates item - Grim Dawn Builds
i think Avycytes managed to cobble together a half decent player pet hybrid using Guardian’s of Death’s gates recently
anyyway,

I just haven’t seen how these items come together or could be combined into a build
then look builds up how other people do it?
GT builds make is relatively simple to see how/if some builds are put together or if exits at all