If you play CS:GO there is 5 types of grenades: flashbang, smoke, molotlove coctail, decoy and classic he.
I think these grenades would be good in Rec Royale and UGC.
How grenades will works: decoy will make sounds of random guns in game.
smoke will make smoke wall for 15sec.
molotove coctail make near explozion paint floor for 7sec
and flashbang everyone near explozion will have paint on 80%screen
all nades will apply your team color.