Sory for the confusion ... i expressed myself poorly.
I mean mod purely from the autor mind, not that kind of mod that takes existing (often datamined) asets and just adds it to some model or fill missing gasps.
And that +15 isnt somethig that bothers me, since in that combat log its not mentioned ...
But additional 1d10 on crit ... effectively making triple damage, seems ridiculous. :-/
But now, when i read that combat log properly ... how the hells he crited with roll 13 ?
If you use gwm it adds +10 dmg on the tooltip for every weapon. But actually it not adding it . Its only works for two handed weapons.
I think the player have +4 from dex weapon+1 and the bugged tooltip. I wanted to report it but i forget.