Not an issue of spikes (lag).
If damage gets too high, it does nothing. (Literally deals negatives or "no effect").
If mob HP gets too high (through buffs), it rolls over, mob has -1 hp (literally dies from ANY damage).
Right now, two of the bosses in T10 and the Xmas portals are nearly at the maximum value. It has to be done because the damage is sooooo high and the mob health has to be so high to compensate.
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HateIs there a reason why HP/damage values are so astronomically high, whilst AC has stayed (relatively) low? Is it because it's easier to scale damage/HP comparatively to AC?
The fix for this long term is probably a combination of both scaling AC and HP/damage properly, so we don't get to a point in the future where this same thing happens again.