https://xcom.com/
Not on sale at steam anymore now but you can get good sales 'other places' (google but only buy from trusted official places unless you like getting scammed).
XCOM 2 = turn based RGP game is better with the DLC called War of the chosen.
Your most powerful soldier = The Reapers (use Shadow and Banish with your Reapers).
Also play at 'rookie level' do not even attempt higher difficulty. Do not use ironman mode. Auto save and save before every battle. Great game if you can get Xcom2 and WOTC both for under $30 just do it