Looking through the (1825) usage stats, the only common abusers are:

at 14.121%

at 7.294%

at 8.206%

at 16.701%

at 13.370%

at 85.782%
The usage stats were for an older metagame however. Using WCOP usage stats though
(only counts revealed moves iirc)
Round 2:

used Tera Blast in 1 of 38 games

used Tera Blast in 2 of 13 games

used Tera Blast in 1 of 2 games

used Tera Blast in 1 of 1 games
No other pokemon used Tera Blast in Round 2
For a larger sample size but older metagame, I'll use Round 1 too.
Round 1:

used Tera Blast in 1 of 272 games

used Tera Blast in 6 of 200 games

used Tera Blast in 6 of 102 games

used Tera Blast in 1 of 56 games

used Tera Blast in 2 of 47 games

used Tera Blast in 1 of 42 games

used Tera Blast in 2 of 32 games

used Tera Blast in 1 of 25 games

used Tera Blast in 1 of 24 games

used Tera Blast in 3 of 23 games

used Tera Blast in 1 of 18 games

used Tera Blast in 1 of 18 games

used Tera Blast in 5 of 11 games

used Tera Blast in 2 of 9 games

used Tera Blast in 1 of 2 games

used Tera Blast in 1 of 1 games