>>42239237
Pretty decent, it gives incredibly high guard boost, but I dont think increases elemental damage reduction much, so you will still take more chip damage than you'd take compared at being a shieldfag in basegame ER
Another problem is that heavy guard stance reduces stamina regen A LOT, so you need to block with high stamina or you will get guard broken regardless
I have heard that doing a foward dash for heavy guard gives invinsibility frames but I have yet to see/feel it
Grab attacks still fuck Guardian over, Ulcerated Tree Spirit being the most notorious case of it