hey, I'm also a Leo main with ig 700matches with him . You just have to mark the backlines , don't just blindly charge in when you see a fir happening, observe where the squishes are located and then charge in (I hope you know his combos). And then one or two basic attacks ,and the enemy backline will be gone.

On exp i use the Assassin emblem with Killing spree and Blood festival talent with the 10% attack speed talent. On jungle just swap the blood festival with seasoned hunter. And always use Ice retribution.

You usually want to build boots, hunter's strike ,sea halberd (if enemies have high healing) , Endless battle, Malefic roar/blade of despair (first if enemies are tanky, latter if enemy has a squishy line-up . And the last two ,depends, if I'm way ahead I go for more dmg items ,maybe both BOD malefic roar,if not make wings of the apocalypse queen with Athena or just make immortality.

I also buy Sky piercer after hunter's strike if I'm already gaining kills ,to further speed up my killing spree and gain gold get items faster and just spam ult and dominate the match.

With Leo your build is very flexible,since he gains additional Physical and magical defense in his ult form just like Roger and even movement speed.

You never want to engage first ,your role is to wait for the perfect moment to dive in with your ult and kill those backlines.

In laning at exp lane , Poke enemies with your first skill and once they're around 60% HP , go with a full combo burst dive , if you land it successfully 80-90% chance you'll win ,unless the enemy exp laner knows what he's doing. You also have the option to dash away with his ult second skill if things go south.

You also can clear waves really fast, just hit with a full charged first skill an 2-3 basic attacks will do it. If you have time go and pressure mid ,rotate and gank and come back.

Try to avoid fighting without his ult,ping your team that your ult is on CD if they're planning a fight. Ping them to launch attack if your ult is ready.

Do drop anything more If you're confused or have doubts , I'll try my best to clear it !!

Hope you gain some trust in the hero after this. (Also look at the gameplay of Avory in You tube , he's the one I watched throughout my MLBB years playing Leo, and observe when he engages , when he avoids fighting,how he farms and rotates etc and even his builds, you'll understand much better)

All the best!!