Question:  Hydra is an album by Within Temptation and contains guest appearances by an American metalcore vocalist best known for being the vocalist of what two bands?
Context: Brian John Williams (born October 25, 1985, in Ocala, Florida) is an American metalcore vocalist.  He formed bands Paddock Park, Sleeping with Sirens and We Are Defiance, his current band. Victoria Bergsman (born 4 May 1977) is a Swedish songwriter, musician, and vocalist best known as singer of the indie pop band The Concretes from 1995 to 2006.  Since announcing her departure from the band on 24 July 2006 she has been recording for her new solo project Taken by Trees.  Bergsman also provided guest vocals for the hit Peter Bjorn and John single "Young Folks" from the album "Writer's Block".  She also starred in a video she conceived for herself set to the song "Temptation" by New Order.  The video is viewable on YouTube under the title "The Temptation of Victoria". Sharon Janny den Adel (born 12 July 1974) is a Dutch singer, songwriter and fashion designer, best known as the lead vocalist and one of the main songwriters in the Dutch symphonic metal band Within Temptation.  She has been a performing musician since the age of 14, and was a founding member of Within Temptation, along with Robert Westerholt, in 1996. Howard Jones (born July 20, 1970) is an American metalcore vocalist, best known as vocalist of the bands Killswitch Engage and Blood Has Been Shed, and as the current vocalist of Light the Torch, formerly known as Devil You Know. "Whole World Is Watching" is a song by Dutch symphonic metal/rock band Within Temptation from their sixth studio album, "Hydra".  It was released in Poland as the third single from the album on January 22, 2014 and was scheduled to have its main release on February 21.  The song features guest vocals from Dave Pirner of Soul Asylum, with Polish rock singer Piotr Rogucki of the band Coma providing vocals on the Polish version of "Hydra". "Nasty Girl" is a song by rapper The Notorious B.I.G.  It was released in 2005 in the US and on January 16, 2006 in the UK.  The single reached #1 in the United Kingdom (this being his first #1 in the country, just under a year after "rival" rapper 2Pac had also achieved his first #1 there also with "Ghetto Gospel").  The song features guest appearances from Jagged Edge, P. Diddy, Avery Storm, and Nelly and the video also contains guest appearances from Pharrell, Usher, Fat Joe, 8 Ball & MJG, Teairra Mari, Jazze Pha, DJ Green Lantern, Naomi Campbell and Memphis Bleek.  It can be found on the album "", a remixed album of Biggie Smalls' work.  The lyrical section rapped by Notorious B.I.G is actually lifted from another of his songs called "Nasty Boy", featured on his second album "Life After Death".  Despite this, the production to the song "Nasty Boy" is completely different from that for "Nasty Girl", and apart from the lyrical sample, and the second verse (rapped by P. Diddy) rapped in the style of Biggie's second verse of Nasty Boy, the two songs bear no similarities.  The chorus, sung by Jagged Edge, which has the line "Grab your titties for B.I.G.", references "Player's Anthem", which he says "Bitches, rub your titties if you love Big Poppa". Botch was an American metalcore band formed in 1993 in Tacoma, Washington.  The band, featuring Brian Cook, Dave Knudson, Tim Latona and Dave Verellen, spent four years as a garage band and released several demos and EPs before signing to Hydra Head Records.  Through the label, Botch released two studio albums: "American Nervoso" (1998) and "We Are the Romans" (1999).  The group toured extensively and internationally in support of their albums with liked-minded bands such as The Blood Brothers, The Dillinger Escape Plan, Ink & Dagger and Jesuit.  Botch struggled to write a third studio album, and in 2002 the group broke up due to tensions among the band members and creative differences.  Hydra Head posthumously released an EP of songs the group had been working on before they split titled "An Anthology of Dead Ends" and a live album documenting their final show titled "061502" in 2006. Hydra is the sixth studio album by Dutch symphonic metal band Within Temptation.  It was released on January 31, 2014 in Europe and on February 4, 2014 in North America.  The album contains guest appearances by singer Howard Jones (ex-Killswitch Engage), rapper Xzibit, metal vocalist Tarja Turunen (ex-Nightwish) and alternative rock singer Dave Pirner (Soul Asylum).  The first single, "Paradise (What About Us?) ", was released on September 27, 2013, and featured Turunen as guest vocalist.  The second single, "Dangerous", was released on December 20, in which Jones provided the male vocals. Robert Westerholt (born 2 January 1975 in Waddinxveen, South Holland, Netherlands) is a Dutch musician, known as the guitarist, unclean vocalist and co-founder of the symphonic metal band Within Temptation.  He also writes music for the band along with his partner and band vocalist Sharon den Adel.  He used to work in human resource management before his career with Within Temptation. Hydra World Tour was a concert tour by Dutch symphonic metal band Within Temptation in support of their sixth studio album, "Hydra", released by Nuclear Blast on 31 January 2014.  To date, it was their eight major tour and their third to see them playing worldwide.  The tour passed over four continents and was divided into several legs according to the local of playing, presenting minor setlist variations from concerts of the same leg and a few more variations from leg to leg.  A special leg was entitled "Theatres on Fire", in which saw the band playing seated shows exclusively on theatres.  The tour was commercially successful and managed the band to play on even bigger spaces, an improvement already seen on their last world tour, as well presenting their first concert at the Wembley Arena and selling out theatre tickets for their theatre seated concerts in the Netherlands.  A live album with footage from the Amsterdam concert was released later in 2014 under the name of Let Us Burn – Elements & Hydra Live in Concert.
Answer: Killswitch Engage and Blood Has Been Shed