Like Bronya, Tingyun is a universal buffer. Her Q restores 50 energy to a character. This is actually broken, compared to Genshin's standards. Raiden restores 12 energy. Of course, the energy costs and generation in HSR are different. But still, if 130 is a more expensive energy cost, Tingyun can restore it to full by using her Q three times. An equivalent in Genshin would be a character that restores say 30 energy per Q (then using it thrice will cover Raiden and Yae 90 cost bursts). Such a character does not exist in Genshin.
Besides that Tingyun gives a universal damage bonus buff for 2 turns with her burst, similar to what Mona does. However Tingyun's buff is for a single ally, whereas Mona's buff is for all allies.
Tingyun also buffs attack with her skill for 3 turns (longer than Yukong). Moreover, the ally receiving her skill buff can deal additional lightning damage (more scaling).