Hi,
I’m an spanish guy that probably had cool fights against many of you in the PvP events, so it’s about time that I say hi to you 
I am proud to say I never spent real money on gems and I’m already lvl 77 (I bought the the game, of course, but I’m a poor guy so I can’t really afford to spend more money than that on it). Managed to get to level 75 with no legendary monsters (my RNG is awful) but with good strategies. At some point I found out a very strong composition of only just 5 monsters (3 of 5 stars, 2 of 4 stars) that can nuke out even parties of 12 strong enemies without issues. Now I finally got 2 legendary monsters on 2 consecutive eggs (Cryokaizer and Cyberwyrm) and I’m getting used to them, but they can’t get even to half of the damage of my previously awesome composition, so I use them just for secondary roles.
I won’t say what is this about because it would suck if everyone uses the same team xD. I only found so far 1 person in PvP fights that also noticed how strong this composition was and he built it differently, with different monsters but same logic. And yup, he nuked 8 of my monsters in a blink before I could even react xD that’s my worst lose (and I even win against some 500+ ranking enemies, despite being around the 1700 or so myself).
Hope to have some good fights against you all soon, awesome game 