The best use of diamonds.

Hey there I have the biggest issue with knowing what to use diamonds on. I feel like I am very weak and I am missing out on allot.
currently I am lvl 96 with 2.5mil power. my heroes are in the low 80's. but I am so freaking weak,Now The question I have is; can i use diamonds to improve my power in some way? what is the best use of diamonds? what are decent lvls for my gear to be at? should I lvl my armour/ boots? So many other questions and chat is always useless so I hope to reach some sort of help from here. Any tips would be most helpful thank you!

Diamonds are best saved for the summoning voucher quest in tower (Buy 1 get 1 free, 40 diamonds each, cheaper than the m.merchant), more warehouse space (if you keep maxing out and going "GOD TRUCKING DARN IT"), or summoning a guild boss (If you need more contribution stars, it gives you a 20% bonus when you boss summon)

Your power will go up faster if you focus on evolving, which takes gold not diamonds (well you can do exchanges for gold... but it's a HORRIBLE waste of diamonds)

As for gear, getting things to around 40-50 for shadow gear (the 4* stuff) is reasonable, but any 5* you'll want to get 60-65 so you can evolve them for the boost it gives. You don't want to heavily invest in shadow gear simply because you'll probably replace them over time. STILL it's better to focus on evolving heroes, as every time you make gear (or try to craft sun chests for 5* gear) you're burning crystals that your future 6*s will need.

It's also smart to hold diamonds till a "Spender" event so you can get a few bonus items for your purchases... always nice to get more free stuff right?

2.5m is one of the "roofs" most players peak at before you really have to dedicate time and a plan to getting stronger, 3m being the roof most players hit before 6* heroes or King Gear.

That sounds about right to be honest, I'm 100 with 2.8mil.

The best investment of your diamonds is the wait for tower tasks. You want to only buy summon vouchers when you encounter the buy one get one free. It comes out to only 40 diamonds each. Once you have 50 you want to only x11 summon when you encounter the task board for getting 25 vouchers back. This will maximize your diamond cost/summon ratio.

Every time you supreme summon you'll get pieces for 6* heros rathim and ophelia. (Not always 100%) Once you can make them you'll notice power spikes. Though they cost a hefty price to boost. Not too mention heroes to refine for fusion stones and 5* monster fodder. Using extra 5*s you can awaken your current team.

As for gear, at level 100 I have about 10 5*, 3 3* and the rest is 4*.

5* gear I always get to 60 and them evolve them. Once everything is 60 I start on making it all 65 and so on and so on.
4* gear I stop touching at level 40.
3* gear I stop at 30~35.

Well then I guess i am on track. I have messed up many times with miss clicks on summons but with the new tower tasks I look forward to getting some more summons out and getting those 6 star pieces. Thank you very much. Also I enjoyed your post in regards to sun chess. I was making the istake of making like 4-10 of them then opening them up. From now on I will save them and open up at 100+