You’ll need to muster your allies to help you in this fight.
In the below video you might take a look at how I ended up defeating the Tree Sentinel.
Keep scrolling for some in-depth tips and tricks to help make this fight far easier.

Note: apologies for the lag prominent during this fight.
I captured the footage on a less stable build of the game.
That’s why I’d recommend getting your hands on the Skeletal Militiamen Ashes.

The point is to distract it.
Endless distractions, all for the low low price of 44 FP.
There you’ll face another, less intimidating, boss: the Tibia Mariner.

Defeat it, and you’ll earn the Skeletal Militiamen Ashes forevermore.
Fight on horseback for an easier time
Torrent is your best friend for this fight.
Wind up heavy attacks with your longest-reach weapon, and let loose while it is distracted.

But one attack in particular may trip you up: the Tree Sentinel’s sideways shield bash attack.
It’s certainly a tough enemy - but far from the toughest boss in this area of the map.
That accolode belongs to theUlcerated Tree Spiritjust nearby.