So here's the deal. Early on it's the best spell to contest bounty runes, bully people on lane, get supports out of the lane and be the king. You can chase people with it, it has low mana cost, it scales well and has low cooldown. You can use it on core after player gets a lasthit. And you can play without blink because of it, just by getting movement speed bonus. And in the lategame with Aghs it turns into 1920 magic damage AoE spell with damage reduction effect

You can get a point into it early on but as as pos 4/5 Axe you want to be active on the map. It can be good to max early if you don't have anything to do at all and just want to farm, but it's not the way to play it. One value point is enough to bully people and the Battle Hunger makes all the work early

Going past laning stage it's your main spell to play. You can still use Battle Hunger to close the gap but it's the AoE non-dispellable crowd control that makes you so useful in midgame fights. However, don't be too aggressive as you're not the tankiest being alive. Usually you want to hide and wait for the opportunity to use Call reliably (e.g. after stun setup or enemy getting close) then either kill the enemy if you're stronger, otherwise you want to disenga

{s:bonus_armor_multiplier}x Battle Hunger Armor Multiplier : Berserker's Call AoE is a good talent, but +120 Battle Hunger DPS, especially in combination with Aghs, is a stupidly high amount of damage

You are going to be brawling a lot, trading your HP all the time. You can replace one Tango for Salve, but Tango works better wor what we're doing

Since you have a low mana pool and gonna fight a lot, you are going to get a lot of charges and, most importantly, a lot of value out of it. Just try to hold your charges instead of usinc stick as a panic button

If you don't really need armor, can't get urn but need out-of-fight regen, have a bad game and is going to jungle or just don't have a lot of money ALTERNATIVE: Phase Boots

Situationally could be purchased early (after urn) but it's better to get later (sometime after Vessel or Aghs)

ALTERNATIVE: Tranquil Boots

Saving teammates and dealing with focus

As you will be a position 4 in your team and going to fight a lot, this is pretty natural to have urn. Not only you're going to get a lot of charges, it will also give you precious mana regen that you need, armor and a little bit more magic damage. It also works well incombination with Berserker's Call. You use Call, disengage from the fight, heal yourself and then come back

Natural item for a tanky brawler like Axe

Additional armor and useful aura

Even more armor! Even more mana! And it's one of the best items to kill enemy cores during Berserker's Call as they can't stop attacking you and you will have a ton of armor anyway so they will take much more damage for sure

vs summons heavy lineups

Against high magic damage lineups

HP, mana regen and a ton of magic damage/degen. Even as a healing source it becomes more powerful in late game

Natural addition to magic heavy build, giving even more slow and armor

May serve as a disengage tool or to save teammates (but usually purchased to get from Diffusal carriers)

Additional initiation

Additional HP and regen amplification from Sange and pretty useful active component for your team

You don't really need Vladmir's by yourself and usually it's the item your position 3 is going to buy but if nobody's going to buy it and your team is heavy on physical damage - why not?

Additional mana/lategame control

vs a lot of dispellable spells

Additional armor for better brawling and to use it for Urn