All passive effects(including permanent boosting effects)on main characters are permanent, including ones from traits like berserker. Which makes the "deal" not worth it for anyone but shapeshifter due to fact they can transform and remove such passives, excluding ones from traits, but those are counted against your passive selection, effectively meaning you have 1 or more less passives to choose from.
The elemental abilities trigger their enemy/ally only specials if they stand on same tile as the elemental skill itself, like fire they are on lava, water if its on water, and so on. I don't know how it can be confusing, but depending on skills unlocked, they might be also shuffled in favor of others. In your case, entangle skill also needs grass in order to activate.
Wait, you are asking how to attack with characters? You click on enemy that is within character's attack range(ranged or melee), then as long their attack type is not "unable", which is for plant summons, certain characters like shadow bringers, and magic orb users but those can drop them in order to attack, often using physical(magical with trait)damage onto the target. Charge movement characters do a free attack if they directly hit the enemy in their movement line, which compensates for their inflexible movement.
Overall this sounds very annoying due to literally talking about systems that the game tells in tooltips how and what to do, well sadly not everything which is something I also have a problem about, but enough to explain vital elements of the game.
