It’s basically a “free” dps buff
HoX one is (in my opinion) the second strongest T5 Major rune behind barbarian one.
How to get it: Get kill achievment from all four T5 bosses once on the character you are going to buy the rune on --> spend 90 T5 tokens and voila, you got a free dps buff
Some of these major runes from T5 are totally useless because they are either so small buffs, or there are other major runes that are simply better (e.g exile/arena rune)
Now what does it buff: All T5 runes are different, however a lot of them have similar traits. HoX one gives:
- +6 seconds duration to Burn to Death DoT (Crazy good)
- 10% extra dmg to BtD
- A 100% finesse hit on Hell Strikes 6 (It’s an additional hard hitting hit at the end of the combo basically, which is doubled in t5-t6 raids)
There’s also minor T5 runes which you only need achievment from the first two bosses in T5 in order to buy, also costs like 1/3 less relics, however I’d recommend people to stay away from that one and just aim for the major rune. The minor runes gives like half of the boost compared to major ones.