If you had to change/buff any hero which one/ s would it be, how and why?
Personally I'd change the level 20 clone abathur talent and rename it to "perfect copy" which would make the clone also copy everything about the hero. Talents, ultimate, stacks, all of it while increasing the duration of the clone by 50%. If you use the ultimate of the cloned hero it increases your next clone cooldown by 75% of the ultimate cooldown that you used (and it stacks for each use) as a clone to not make it too OP. (I think it's more fitting because it aligns with his ideology of pursuing perfection, thus having a perfect version of an ability would be more in-line with his character and the ult's theme)
I'd give leoric talents that benefit his trait and perhaps give him summons as talents or/ and give him baseline summons which are summoned by using D. (leoric lacks ranged capabilities or pve against anything other than minions, sometimes he's useless when enemies have an advantage over him because he can't survive at close range and ends up sitting at the back line waiting for a chance to strike if it even comes. For lore reasons he's a king that is obsessed with loyalty/servants while summoning undead minions to aid him in his respective game. It's the most thematic thing that he doesn't have arguably)
I'd increase the regeneration of his rime talent while CCd massively and make Icebound fortitude a baseline ability that gets unlocked after 30 stacks of frostmorne. (Arthas isn't doing great right now, and he's my 4th most played character so I've experienced it)