** Don't forget we have easy way to give 3+ save (Battlemith + prayer), and even 2+ with the Runesmiter. Now take a unit of 20 (they have the horde reduction cost, unlike Vulkites...); with a 3+ (or 2+ for 1 turn) save and a 4+ FnP, they will not die easily, and they will hit like a truck in return: 2 attacks each 3+/3+/-1 2d, with a range of 2", they can fight on 2 ranks... this is borderline nasty (without even including our runes, you know like rerolls hit roles of 1 or add -1 to Rend...). And you can even give them rerolls all failed wounds rolls, and making them attack twice in the combat phase with a Battalion (if anything survives the first wave to begin with).Vulkite and Auric are good, but Hearthguard Berzerkers are really, really, good. And oh, we can make them battlelines with a Runefather as general.
** New FAQ put the unit size limit from 30 to 20, but because we still have the horde reduction cost it remain our best unit, and it is even better in certain matchup to play 2 unit of 20 rather than one unit of 30 for the map control
*'''[https://www.games-workshop.com/resources/PDF/AoS_Warscrolls/AoS_Fyreslayers_WSCards_The_Chosen_Axes_EN.pdf Chosen Axes]:''' The Fyreslayer Shadespire Warband. Required to be taken with Fjul-Grimnir. For 40 points you get 3 Duardin, 1 with 2 4+, 3+ Rend-, 2 Damage Attack (rerolling to hits), 1 with 2 4+, 3+, Rend - 1 damage attack (also rerolling to hits) and 1 with 2, 4+, 3+, Rend -1, 1 Damage attacks. They also never take battleshock and get +1 to wound when within 3 of Fjul-Grimnir. Unfortunately, they only have a 5+ save and a 6+ FNP, and for only 3 wounds, that's not a lot. Given that they cost the same as 1/3rd of a unit of Vulkite Berzerkers, it's hard to justify taking them, and thus hard to justify Fjul-Grimnir.