So they nerf a 5(FIVE!)% proc ability which resets and make lava burst instant. At the same time they give paladins an ability that does comparable damage to lava burst (with all runes and set bonuses), requires no setup and resets on every crit. Oh and you can also heal with it.
So let’s break this down:
Shaman: Lava Burst: 2 sec cast, 8 sec cd, requires flame shock (dispellable, resistable) on target to 100% crit. Otherwise it has somewhere around ~15-20% crit chance as it doesn’t get any crit from talents, only whatever you have on your gear + intellect. Has a 5% per flame shock tick (every 3 seconds, dispellable, resistable) to reset and become instant.
Paladin: Holy shock. Instant out of the box, 6 sec cd from rune and resets on crits from rune, also same rune increases its damage and healing by a whoopping 50%. Gives spell damage equal to int (~300 given the kind of gear a holy paladin would probably wear) from rune - the absolute highest among all other similar effects on other classes. Has at least 48% (5% base + 5% talent + 18% rune (also absolute highest among other classes) + 20% zg set (also this set gives another +50% damage bonus)) chance to crit. In reality this is somewhere around ~70% or even more if you take into account spell crit from items + spell crit from intellect. Can also be used to heal self or others. Refunds full mana cost if used as a heal and crits through a talent. Oh and there’s no such thing as holy resistance in the game.
Do I need to say more?
P.S. It’s also very convenient that all updated bwl and zg gear has had its ‘+healing’ stats changed to ‘+healing AND damage’. What a conincedence.