Giving all the other heroes special and tiles 48% damage boost for 4 rounds is in many cases more effective than straight damage like liannas. Also depending on what level of titan you are up against the healing can be useful aswell to save items or just being able to focus on items that add damage.
I think in general you do lots of the damage against titans with tiles rather than specials. So a combo of added damage and lowered defence is effective. Wu is troublesome since he also blinds your own heroes. After recent update blind has become stronger which is a nerf to wu.
Because if this Wu is a gamble and you will find you get really high and really low results. I am not sure he is worth it compared to other strategies when looking at total damage. Usable of course if you want to try and raise your personal best one hit.
Another strategy is to focus on bringing lots of heroes of same colour that matches the titans weakness. I’ve attacked green titans with full red team a few times with good result.
I find I like using heroes that add damage but also helps with sustainability. I like using joon since he keeps titan blinded (stronger than arrows), I use Athena or pulveriser hero to keep defence lowered and I use bold to keep attack boosted. If I had a hero like scarlet that kept titans attack lowered I would prob use her aswell.
This above is good team to do good damage without needing lots of items. If I want to bring out the guns I might switch it up a bit and use mana potions at start of fight and use tornadoes during.