>>32052797I've tried like 5 different builds and for the Battle Tree I had the most success with a Bold, Contrary, AssVest, EVs in HP/Def one. Leaf Storm, Giga Drain, Hidden Power, Weather Ball. Thanks to the bulk it can check most things that would endanger Toxa and still take them out thanks to the boosts from Leaf Storm Contrary. Very rarely you'll use any of the other moves though Giga Drain allows to heal and keep sweeping every now and then.
Specially Defensive with support moves+Leaf Storm also did alright, but it often underperformed because of the lack of physical Def to tank EQs and shit, hence why I tried AssVest. I expected not having Synthesis being a problem, but it worked surprisingly well.
As we all know it is NOT a very strong mon so you can often find yourself wishing you had something better, but I love its design and had to enjoy it somehow.