yeah it really overshadows the other keystones, i mean, i love the concept of the keystones but they just dont seem balanced, with thunderlords being an overpowered keystone and that one where u get extra hp per siege minion killed is quite underpowered (20 minutes into a game and people have an extra 150 hp) its very lackluster next to a keystone that will rob you of that bonus hp because you were hit 3 times....
meanwhile yas gets garentee heals (on crits) and tanks can steal a good 60 - 130 hp every 4 seconds in combat
basically what im getting at is there are only 5 real choices for keystones (havent mentioned deathfire but yeah, deathfire) the way i see it and when everyone is choosing thunderlords (even over deathfire) it shows how powerful of a keystone it is when compared to most other keystones