Riven's abilities charge her blade, and her basic attacks expend charges to deal an additional damage.
1
BROKEN WINGS
Riven lashes out in a series of strikes. This ability can be reactivated three times in a short time frame with the third hit knocking back nearby enemies.
2
KI BURST
Riven emits a Ki Burst, damaging and stunning nearby enemies.
3
VALOR
Riven steps forward a short distance and blocks incoming damage.
Ult
BLADE OF THE EXILE
Riven empowers her keepsake weapon with energy, and gains Attack Damage and Range. During this time, she also gains the ability to use Wind Slash, a powerful ranged attack, once. Taking down a target with her will extend the ability time and grant a re-cast of Wind Slash.
Ability descriptions from the official Wild Rift website.
This page is for League of Legends: Wild Rift (the mobile game), not League of Legends on PC. A Japanese version with guides and matchup notes is available: 日本語版.