make Axe all spells scale from ult in some way, my suggestions is this:
Berserker's Call: Armor Bonus: 25 > 13/17/21/25 (33) but make Duration: 2/2.4/2.8/3.2 > 3 sec, mana cost from 80/90/100/110 > 70/80/90/100, Ult increase buff duration by 1 sec per 5 stacks
Battle Hunger: Cast Range: 700/775/850/925 > 800, Damage type: physical > Pure, Base Damage per Second: 10/15/20/25 + 1x armor, Move Speed Slow: 11%/19%/27%/35% (12% slow > 10%, removed aghm Enemy Armor Reduction: 7, aghm still give +7 armor per enemy (since the point of – armor on aghm before was to buff W dps), ult add 5/7/10 dps/stack
Counter Helix: i would rework it to be more consistent, Radius: 275 > 300 (same as Call), Proc Chance: 17%/18%/19%/20% ( 27%/28%/29%/30% ) > flat 5/4/3/2 sec cd spin that proc on any unit attack (so it make no difference if u fight inside creep wave or 1 vs 1 in a jungle), Damage: 60/100/140/180 ( 90/130/170/210 ) > 30/50/70/90 ( lvl 15 talent +15 Helix dmg 45/65/85/105), Ult add 10/15/20 dmg/stack
Culling Blade: removed Kill Move Speed Bonus Radius: 900 (no ms for allies), cd 100/85/70 >100/80/60, now when Axe kill a hero he gets Kill Move Speed Bonus: 20%/25%/30% and Ult buff for 20 sec that reset ult cd on kills and reduce next ult cost from 100/125/150 > 0, when buff ends ult go on cd (its to encourage multi kills when u can get them but guarantee that it will go on cd) same 1/1.5/2 armor per stack
Source: https://www.reddit.com/r/DotA2/comments/zyc7qd/next_patch_axe_buff_that_would_be_cool/